Adjusting a data storage address mapping in a maintenance free storage container

ABSTRACT

A method includes sending, by a computing device, an access request to one or more site controllers. The method further includes identifying, by a site controller, storage containers based on DSN addresses. The method includes sending, by the site controller, the access request to the identified storage containers. The method includes interpreting, by a container controller, the access request to identify storage units affiliated with some of the DSN addresses. The method includes determining, by the container controller, whether the storage units are in a storage failure mode. The method includes when the storage units are in the storage failure mode, determining, by the container controller, whether to rebuild, to change virtual to physical address mapping, or to migrate encoded data slices. The method includes, when the encoded data slices are to be rebuild, facilitating, by the container controller, rebuilding of the encoded data slices.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. §120 as a continuation of U.S. Utility application Ser. No.13/450,186, entitled “ADJUSTING A DATA STORAGE ADDRESS MAPPING IN AMAINTENANCE FREE STORAGE CONTAINER”, filed Apr. 18, 2012, issuing asU.S. Pat. No. 9,141,458 on Sep. 22, 2015, which claims priority pursuantto 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/483,852,entitled “CONTAINER BASED DISPERSED STORAGE NETWORK”, filed May 9, 2011,both of which are hereby incorporated herein by reference in theirentirety and made part of the present U.S. Utility Patent Applicationfor all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to computing systems and moreparticularly to data storage solutions within such computing systems.

2. Description of Related Art

Computers are known to communicate, process, and store data. Suchcomputers range from wireless smart phones to data centers that supportmillions of web searches, stock trades, or on-line purchases every day.In general, a computing system generates data and/or manipulates datafrom one form into another. For instance, an image sensor of thecomputing system generates raw picture data and, using an imagecompression program (e.g., JPEG, MPEG, etc.), the computing systemmanipulates the raw picture data into a standardized compressed image.

With continued advances in processing speed and communication speed,computers are capable of processing real time multimedia data forapplications ranging from simple voice communications to streaming highdefinition video. As such, general-purpose information appliances arereplacing purpose-built communications devices (e.g., a telephone). Forexample, smart phones can support telephony communications but they arealso capable of text messaging and accessing the internet to performfunctions including email, web browsing, remote applications access, andmedia communications (e.g., telephony voice, image transfer, musicfiles, video files, real time video streaming. etc.).

Each type of computer is constructed and operates in accordance with oneor more communication, processing, and storage standards. As a result ofstandardization and with advances in technology, more and moreinformation content is being converted into digital formats. Forexample, more digital cameras are now being sold than film cameras, thusproducing more digital pictures. As another example, web-basedprogramming is becoming an alternative to over the air televisionbroadcasts and/or cable broadcasts. As further examples, papers, books,video entertainment, home video, etc. are now being stored digitally,which increases the demand on the storage function of computers.

A typical computer storage system includes one or more memory devicesaligned with the needs of the various operational aspects of thecomputer's processing and communication functions. Generally, theimmediacy of access dictates what type of memory device is used. Forexample, random access memory (RAM) memory can be accessed in any randomorder with a constant response time, thus it is typically used for cachememory and main memory. By contrast, memory device technologies thatrequire physical movement such as magnetic disks, tapes, and opticaldiscs, have a variable response time as the physical movement can takelonger than the data transfer, thus they are typically used forsecondary memory (e.g., hard drive, backup memory, etc.).

A computer's storage system will be compliant with one or more computerstorage standards that include, but are not limited to, network filesystem (NFS), flash file system (FFS), disk file system (DFS), smallcomputer system interface (SCSI), internet small computer systeminterface (iSCSI), file transfer protocol (FTP), and web-baseddistributed authoring and versioning (WebDAV). These standards specifythe data storage format (e.g., files, data objects, data blocks,directories, etc.) and interfacing between the computer's processingfunction and its storage system, which is a primary function of thecomputer's memory controller.

Despite the standardization of the computer and its storage system,memory devices fail; especially commercial grade memory devices thatutilize technologies incorporating physical movement (e.g., a discdrive). For example, it is fairly common for a disc drive to routinelysuffer from bit level corruption and to completely fail after threeyears of use. One solution is to utilize a higher-grade disc drive,which adds significant cost to a computer.

Another solution is to utilize multiple levels of redundant disc drivesto replicate the data into two or more copies. One such redundant driveapproach is called redundant array of independent discs (RAID). In aRAID device, a RAID controller adds parity data to the original databefore storing it across the array. The parity data is calculated fromthe original data such that the failure of a disc will not result in theloss of the original data. For example, RAID 5 uses three discs toprotect data from the failure of a single disc. The parity data, andassociated redundancy overhead data, reduces the storage capacity ofthree independent discs by one third (e.g., n−1=capacity). RAID 6 canrecover from a loss of two discs and requires a minimum of four discswith a storage capacity of n−2.

While RAID addresses the memory device failure issue, it is not withoutits own failure issues that affect its effectiveness, efficiency andsecurity. For instance, as more discs are added to the array, theprobability of a disc failure increases, which increases the demand formaintenance. For example, when a disc fails, it needs to be manuallyreplaced before another disc fails and the data stored in the RAIDdevice is lost. To reduce the risk of data loss, data on a RAID deviceis typically copied on to one or more other RAID devices. While thisaddresses the loss of data issue, it raises a security issue sincemultiple copies of data are available, which increases the chances ofunauthorized access. Further, as the amount of data being stored grows,the overhead of RAID devices becomes a non-trivial efficiency issue.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a computingsystem in accordance with the present invention;

FIG. 2 is a schematic block diagram of an embodiment of a computing corein accordance with the present invention;

FIG. 3 is a schematic block diagram of an embodiment of a distributedstorage processing unit in accordance with the present invention;

FIG. 4 is a schematic block diagram of an embodiment of a grid module inaccordance with the present invention;

FIG. 5 is a diagram of an example embodiment of error coded data slicecreation in accordance with the present invention;

FIG. 6 is a schematic block diagram of another embodiment of a computingsystem in accordance with the present invention;

FIG. 7A is a schematic block diagram of another embodiment of acomputing system in accordance with the present invention;

FIG. 7B is a flowchart illustrating an example of assigning a dispersedstorage network (DSN) address range in accordance with the presentinvention;

FIG. 8A is a schematic block diagram of another embodiment of acomputing system in accordance with the present invention;

FIG. 8B is a schematic block diagram of an embodiment of anauthentication system in accordance with the present invention;

FIG. 8C is a flowchart illustrating an example of processing a storageserver access request in accordance with the present invention;

FIG. 9A is a schematic block diagram of another embodiment of acomputing system in accordance with the present invention;

FIG. 9B is a schematic block diagram of an embodiment of a maintenancefree storage container in accordance with the present invention;

FIG. 9C is a table illustrating an example of a slice name to nextlocation table in accordance with the present invention;

FIG. 9D is a table illustrating another example of a slice name to nextlocation table in accordance with the present invention;

FIG. 9E is a table illustrating another example of a slice name to nextlocation table in accordance with the present invention;

FIG. 9F is a schematic block diagram of another embodiment of acomputing system in accordance with the present invention;

FIG. 9G is a table illustrating another example of a slice name to nextlocation table in accordance with the present invention;

FIG. 9H includes tables illustrating more examples of slice name to nextlocation tables in accordance with the present invention;

FIG. 9I is a schematic block diagram of another embodiment of acomputing system in accordance with the present invention;

FIG. 10 is a flowchart illustrating an example of retrieving a datasegment in accordance with the present invention;

FIG. 11 is a flowchart illustrating an example of rebuilding an encodedslice in accordance with the present invention;

FIG. 12A is a schematic block diagram of another embodiment of acomputing system in accordance with the present invention; and

FIG. 12B is a flowchart illustrating another example of rebuilding anencoded slice in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of a computing system 10 thatincludes one or more of a first type of user devices 12, one or more ofa second type of user devices 14, at least one distributed storage (DS)processing unit 16, at least one DS managing unit 18, at least onestorage integrity processing unit 20, a distributed storage network(DSN) memory 22 coupled via a network 24 and at least one maintenancefree storage container 190 coupled via network 24. The network 24 mayinclude one or more wireless and/or wire lined communication systems;one or more private intranet systems and/or public internet systems;and/or one or more local area networks (LAN) and/or wide area networks(WAN).

The DSN memory 22 includes a plurality of distributed storage (DS) units36 for storing data of the computing system 10. Each of the DS units 36includes a processing module and memory and may be located at ageographically different site than the other DS units (e.g., one inChicago, one in Milwaukee, etc.). The maintenance free storage container190 includes a plurality of virtual storage servers 216 and a pluralityof storage servers 1-U for storing data of the computing system 10. Themaintenance free storage container 190 allows for multiple storageservers of the plurality of storage servers 1-U to be in a failure modewithout replacement. Each of the virtual store servers 216 includes aprocessing module to transfer data (e.g., slices 11) between thecomputing system 10 and at least some of the storage servers 1-U inaccordance with a mapping. Each storage server of the plurality ofstorage servers 1-U includes a processing module and memory to storedata (e.g., slices 11).

Each of the user devices 12-14, the DS processing unit 16, the DSmanaging unit 18, and the storage integrity processing unit 20 may be aportable computing device (e.g., a social networking device, a gamingdevice, a cell phone, a smart phone, a personal digital assistant, adigital music player, a digital video player, a laptop computer, ahandheld computer, a video game controller, and/or any other portabledevice that includes a computing core) and/or a fixed computing device(e.g., a personal computer, a computer server, a cable set-top box, asatellite receiver, a television set, a printer, a fax machine, homeentertainment equipment, a video game console, and/or any type of homeor office computing equipment). Such a portable or fixed computingdevice includes a computing core 26 and one or more interfaces 30, 32,and/or 33. An embodiment of the computing core 26 will be described withreference to FIG. 2.

With respect to the interfaces, each of the interfaces 30, 32, and 33includes software and/or hardware to support one or more communicationlinks via the network 24 indirectly and/or directly. For example,interfaces 30 support a communication link (wired, wireless, direct, viaa LAN, via the network 24, etc.) between the first type of user device14 and the DS processing unit 16. As another example, DSN interface 32supports a plurality of communication links via the network 24 betweenthe DSN memory 22 and the DS processing unit 16, the first type of userdevice 12, and/or the storage integrity processing unit 20. As yetanother example, interface 33 supports a communication link between theDS managing unit 18 and any one of the other devices and/or units 12,14, 16, 20, and/or 22 via the network 24.

In general and with respect to data storage, the system 10 supportsthree primary functions: distributed network data storage management,distributed data storage and retrieval, and data storage integrityverification. In accordance with these three primary functions, data canbe distributedly stored in a plurality of physically different locationsand subsequently retrieved in a reliable and secure manner regardless offailures of individual storage devices, failures of network equipment,the duration of storage, the amount of data being stored, attempts athacking the data, etc.

The DS managing unit 18 performs distributed network data storagemanagement functions, which include establishing distributed datastorage parameters, performing network operations, performing networkadministration, and/or performing network maintenance. The DS managingunit 18 establishes the distributed data storage parameters (e.g.,allocation of virtual DSN memory space, distributed storage parameters,security parameters, billing information, user profile information,etc.) for one or more of the user devices 12-14 (e.g., established forindividual devices, established for a user group of devices, establishedfor public access by the user devices, etc.). For example, the DSmanaging unit 18 coordinates the creation of a vault (e.g., a virtualmemory block) within the DSN memory 22 for a user device (for a group ofdevices, or for public access). The DS managing unit 18 also determinesthe distributed data storage parameters for the vault. In particular,the DS managing unit 18 determines a number of slices (e.g., the numberthat a data segment of a data file and/or data block is partitioned intofor distributed storage) and a read threshold value (e.g., the minimumnumber of slices required to reconstruct the data segment).

As another example, the DS managing module 18 creates and stores,locally or within the DSN memory 22, user profile information. The userprofile information includes one or more of authentication information,permissions, and/or the security parameters. The security parameters mayinclude one or more of encryption/decryption scheme, one or moreencryption keys, key generation scheme, and data encoding/decodingscheme.

As yet another example, the DS managing unit 18 creates billinginformation for a particular user, user group, vault access, publicvault access, etc. For instance, the DS managing unit 18 tracks thenumber of times a user accesses a private vault and/or public vaults,which can be used to generate a per-access bill. In another instance,the DS managing unit 18 tracks the amount of data stored and/orretrieved by a user device and/or a user group, which can be used togenerate a per-data-amount bill.

The DS managing unit 18 also performs network operations, networkadministration, and/or network maintenance. As at least part ofperforming the network operations and/or administration, the DS managingunit 18 monitors performance of the devices and/or units of the system10 for potential failures, determines the devices' and/or units'activation status, determines the devices' and/or units' loading, andany other system level operation that affects the performance level ofthe system 10. For example, the DS managing unit 18 receives andaggregates network management alarms, alerts, errors, statusinformation, performance information, and messages from the devices12-14 and/or the units 16, 20, 22. For example, the DS managing unit 18receives a simple network management protocol (SNMP) message regardingthe status of the DS processing unit 16.

The DS managing unit 18 performs the network maintenance by identifyingequipment within the system 10 that needs replacing, upgrading,repairing, and/or expanding. For example, the DS managing unit 18determines that the DSN memory 22 needs more DS units 36 or that one ormore of the DS units 36 needs updating.

The second primary function (i.e., distributed data storage andretrieval) begins and ends with a user device 12-14. For instance, if asecond type of user device 14 has a data file 38 and/or data block 40 tostore in the DSN memory 22, it sends the data file 38 and/or data block40 to the DS processing unit 16 via its interface 30. As will bedescribed in greater detail with reference to FIG. 2, the interface 30functions to mimic a conventional operating system (OS) file systeminterface (e.g., network file system (NFS), flash file system (FFS),disk file system (DFS), file transfer protocol (FTP), web-baseddistributed authoring and versioning (WebDAV), etc.) and/or a blockmemory interface (e.g., small computer system interface (SCSI), internetsmall computer system interface (iSCSI), etc.). In addition, theinterface 30 may attach a user identification code (ID) to the data file38 and/or data block 40.

The DS processing unit 16 receives the data file 38 and/or data block 40via its interface 30 and performs a distributed storage (DS) process 34thereon (e.g., an error coding dispersal storage function). The DSprocessing 34 begins by partitioning the data file 38 and/or data block40 into one or more data segments, which is represented as Y datasegments. For example, the DS processing 34 may partition the data file38 and/or data block 40 into a fixed byte size segment (e.g., 2¹ to2^(n) bytes, where n=>2) or a variable byte size (e.g., change byte sizefrom segment to segment, or from groups of segments to groups ofsegments, etc.).

For each of the Y data segments, the DS processing 34 error encodes(e.g., forward error correction (FEC), information dispersal algorithm,or error correction coding) and slices (or slices then error encodes)the data segment into a plurality of error coded (EC) data slices 42-48,which is represented as X slices per data segment. The number of slices(X) per segment, which corresponds to a number of pillars n, is set inaccordance with the distributed data storage parameters and the errorcoding scheme. For example, if a Reed-Solomon (or other FEC scheme) isused in an n/k system, then a data segment is divided into n slices,where k number of slices is needed to reconstruct the original data(i.e., k is the threshold). As a few specific examples, the n/k factormay be 5/3; 6/4; 8/6; 8/5; 16/10.

For each EC slice 42-48, the DS processing unit 16 creates a uniqueslice name and appends it to the corresponding EC slice 42-48. The slicename includes universal DSN memory addressing routing information (e.g.,virtual memory addresses in the DSN memory 22) and user-specificinformation (e.g., user ID, file name, data block identifier, etc.).

The DS processing unit 16 transmits the plurality of EC slices 42-48 toat least one of a plurality of DS units 36 of the DSN memory 22 and aplurality of virtual storage servers 216 of the maintenance free storagecontainer 190 via the DSN interface 32 and the network 24. The DSNinterface 32 formats each of the slices for transmission via the network24. For example, the DSN interface 32 may utilize an internet protocol(e.g., TCP/IP, etc.) to packetize the EC slices 42-48 for transmissionvia the network 24.

The number of DS units 36 receiving the EC slices 42-48 is dependent onthe distributed data storage parameters established by the DS managingunit 18. For example, the DS managing unit 18 may indicate that eachslice is to be stored in a different DS unit 36. As another example, theDS managing unit 18 may indicate that like slice numbers of differentdata segments are to be stored in the same DS unit 36. For example, thefirst slice of each of the data segments is to be stored in a first DSunit 36, the second slice of each of the data segments is to be storedin a second DS unit 36, etc. In this manner, the data is encoded anddistributedly stored at physically diverse locations to improve datastorage integrity and security.

Each DS unit 36 that receives an EC slice 42-48 for storage translatesthe virtual DSN memory address of the slice into a local physicaladdress for storage. Accordingly, each DS unit 36 maintains a virtual tophysical memory mapping to assist in the storage and retrieval of data.

The first type of user device 12 performs a similar function to storedata in the DSN memory 22 with the exception that it includes the DSprocessing. As such, the device 12 encodes and slices the data fileand/or data block it has to store. The device then transmits the slices11 to at least one of the DSN memory 22 and the maintenance free storagecontainer 190 via its DSN interface 32 and the network 24.

For a second type of user device 14 to retrieve a data file or datablock from memory, it issues a read command via its interface 30 to theDS processing unit 16. The DS processing unit 16 performs the DSprocessing 34 to identify the DS units 36 storing the slices of the datafile and/or data block based on the read command. The DS processing unit16 may also communicate with the DS managing unit 18 to verify that theuser device 14 is authorized to access the requested data.

Assuming that the user device is authorized to access the requesteddata, the DS processing unit 16 issues slice read commands to at least athreshold number of the DS units 36 storing the requested data (e.g., toat least 10 DS units for a 16/10 error coding scheme). Each of the DSunits 36 receiving the slice read command, verifies the command,accesses its virtual to physical memory mapping, retrieves the requestedslice, or slices, and transmits it to the DS processing unit 16.

Once the DS processing unit 16 has received a read threshold number ofslices for a data segment, it performs an error decoding function andde-slicing to reconstruct the data segment. When Y number of datasegments has been reconstructed, the DS processing unit 16 provides thedata file 38 and/or data block 40 to the user device 14. Note that thefirst type of user device 12 performs a similar process to retrieve adata file and/or data block.

The storage integrity processing unit 20 performs the third primaryfunction of data storage integrity verification. In general, the storageintegrity processing unit 20 periodically retrieves slices 45, and/orslice names, of a data file or data block of a user device to verifythat one or more slices have not been corrupted or lost (e.g., the DSunit failed). The retrieval process mimics the read process previouslydescribed.

If the storage integrity processing unit 20 determines that one or moreslices is corrupted or lost, it rebuilds the corrupted or lost slice(s)in accordance with the error coding scheme. The storage integrityprocessing unit 20 stores the rebuild slice, or slices, in theappropriate DS unit(s) 36 in a manner that mimics the write processpreviously described.

FIG. 2 is a schematic block diagram of an embodiment of a computing core26 that includes a processing module 50, a memory controller 52, mainmemory 54, a video graphics processing unit 55, an input/output (IO)controller 56, a peripheral component interconnect (PCI) interface 58,an IO interface 60, at least one IO device interface module 62, a readonly memory (ROM) basic input output system (BIOS) 64, and one or morememory interface modules. The memory interface module(s) includes one ormore of a universal serial bus (USB) interface module 66, a host busadapter (HBA) interface module 68, a network interface module 70, aflash interface module 72, a hard drive interface module 74, and a DSNinterface module 76. Note the DSN interface module 76 and/or the networkinterface module 70 may function as the interface 30 of the user device14 of FIG. 1. Further note that the IO device interface module 62 and/orthe memory interface modules may be collectively or individuallyreferred to as IO ports.

FIG. 3 is a schematic block diagram of an embodiment of a dispersedstorage (DS) processing module 34 of user device 12 and/or of the DSprocessing unit 16. The DS processing module 34 includes a gatewaymodule 78, an access module 80, a grid module 82, and a storage module84. The DS processing module 34 may also include an interface 30 and theDSnet interface 32 or the interfaces 68 and/or 70 may be part of userdevice 12 or of the DS processing unit 16. The DS processing module 34may further include a bypass/feedback path between the storage module 84to the gateway module 78. Note that the modules 78-84 of the DSprocessing module 34 may be in a single unit or distributed acrossmultiple units.

In an example of storing data, the gateway module 78 receives anincoming data object that includes a user ID field 86, an object namefield 88, and the data object field 40 and may also receivecorresponding information that includes a process identifier (e.g., aninternal process/application ID), metadata, a file system directory, ablock number, a transaction message, a user device identity (ID), a dataobject identifier, a source name, and/or user information. The gatewaymodule 78 authenticates the user associated with the data object byverifying the user ID 86 with the managing unit 18 and/or anotherauthenticating unit.

When the user is authenticated, the gateway module 78 obtains userinformation from the management unit 18, the user device, and/or theother authenticating unit. The user information includes a vaultidentifier, operational parameters, and user attributes (e.g., userdata, billing information, etc.). A vault identifier identifies a vault,which is a virtual memory space that maps to a set of DS storage units36. For example, vault 1 (i.e., user 1's DSN memory space) includeseight DS storage units (X=8 wide) and vault 2 (i.e., user 2's DSN memoryspace) includes sixteen DS storage units (X=16 wide). The operationalparameters may include an error coding algorithm, the width n (number ofpillars X or slices per segment for this vault), a read threshold T, awrite threshold, an encryption algorithm, a slicing parameter, acompression algorithm, an integrity check method, caching settings,parallelism settings, and/or other parameters that may be used to accessthe DSN memory layer.

The gateway module 78 uses the user information to assign a source name35 to the data. For instance, the gateway module 78 determines thesource name 35 of the data object 40 based on the vault identifier andthe data object. For example, the source name may contain a fileidentifier (ID), a vault generation number, a reserved field, and avault identifier (ID). As another example, the gateway module 78 maygenerate the file ID based on a hash function of the data object 40.Note that the gateway module 78 may also perform message conversion,protocol conversion, electrical conversion, optical conversion, accesscontrol, user identification, user information retrieval, trafficmonitoring, statistics generation, configuration, management, and/orsource name determination.

The access module 80 receives the data object 40 and creates a series ofdata segments 1 through Y 90-92 in accordance with a data storageprotocol (e.g., file storage system, a block storage system, and/or anaggregated block storage system). The number of segments Y may be chosenor randomly assigned based on a selected segment size and the size ofthe data object. For example, if the number of segments is chosen to bea fixed number, then the size of the segments varies as a function ofthe size of the data object. For instance, if the data object is animage file of 4,194,304 eight bit bytes (e.g., 33,554,432 bits) and thenumber of segments Y=131,072, then each segment is 256 bits or 32 bytes.As another example, if segment size is fixed, then the number ofsegments Y varies based on the size of data object. For instance, if thedata object is an image file of 4,194,304 bytes and the fixed size ofeach segment is 4,096 bytes, then the number of segments Y=1,024. Notethat each segment is associated with the same source name.

The grid module 82 receives the data segments and may manipulate (e.g.,compression, encryption, cyclic redundancy check (CRC), etc.) each ofthe data segments before performing an error coding function of theerror coding dispersal storage function to produce a pre-manipulateddata segment. After manipulating a data segment, if applicable, the gridmodule 82 error encodes (e.g., Reed-Solomon, Convolution encoding,Trellis encoding, etc.) the data segment or manipulated data segmentinto X error coded data slices 42-44.

The value X, or the number of pillars (e.g., X=16), is chosen as aparameter of the error coding dispersal storage function. Otherparameters of the error coding dispersal function include a readthreshold T, a write threshold W, etc. The read threshold (e.g., T=10,when X=16) corresponds to the minimum number of error-free error codeddata slices required to reconstruct the data segment. In other words,the DS processing module 34 can compensate for X-T (e.g., 16−10=6)missing error coded data slices per data segment. The write threshold Wcorresponds to a minimum number of DS storage units that acknowledgeproper storage of their respective data slices before the DS processingmodule indicates proper storage of the encoded data segment. Note thatthe write threshold is greater than or equal to the read threshold for agiven number of pillars (X).

For each data slice of a data segment, the grid module 82 generates aunique slice name 37 and attaches it thereto. The slice name 37 includesa universal routing information field and a vault specific field and maybe 48 bytes (e.g., 24 bytes for each of the universal routinginformation field and the vault specific field). As illustrated, theuniversal routing information field includes a slice index, a vault ID,a vault generation, and a reserved field. The slice index is based onthe pillar number and the vault ID and, as such, is unique for eachpillar (e.g., slices of the same pillar for the same vault for anysegment will share the same slice index). The vault specific fieldincludes a data name, which includes a file ID and a segment number(e.g., a sequential numbering of data segments 1-Y of a simple dataobject or a data block number).

Prior to outputting the error coded data slices of a data segment, thegrid module may perform post-slice manipulation on the slices. Ifenabled, the manipulation includes slice level compression, encryption,CRC, addressing, tagging, and/or other manipulation to improve theeffectiveness of the computing system.

When the error coded data slices of a data segment are ready to beoutputted, the grid module 82 determines which of the DS storage units36 will store the EC data slices based on a dispersed storage memorymapping associated with the user's vault and/or DS storage unitattributes. The DS storage unit attributes may include availability,self-selection, performance history, link speed, link latency,ownership, available DSN memory, domain, cost, a prioritization scheme,a centralized selection message from another source, a lookup table,data ownership, and/or any other factor to optimize the operation of thecomputing system. Note that the number of DS storage units 36 is equalto or greater than the number of pillars (e.g., X) so that no more thanone error coded data slice of the same data segment is stored on thesame DS storage unit 36. Further note that EC data slices of the samepillar number but of different segments (e.g., EC data slice 1 of datasegment 1 and EC data slice 1 of data segment 2) may be stored on thesame or different DS storage units 36.

The storage module 84 performs an integrity check on the outboundencoded data slices and, when successful, identifies a plurality of DSstorage units based on information provided by the grid module 82. Thestorage module 84 then outputs the encoded data slices 1 through X ofeach segment 1 through Y to the DS storage units 36. Each of the DSstorage units 36 stores its EC data slice(s) and maintains a localvirtual DSN address to physical location table to convert the virtualDSN address of the EC data slice(s) into physical storage addresses.

In an example of a read operation, the user device 12 and/or 14 sends aread request to the DS processing unit 16, which authenticates therequest. When the request is authentic, the DS processing unit 16 sendsa read message to each of the DS storage units 36 storing slices of thedata object being read. The slices are received via the DSnet interface32 and processed by the storage module 84, which performs a parity checkand provides the slices to the grid module 82 when the parity check wassuccessful. The grid module 82 decodes the slices in accordance with theerror coding dispersal storage function to reconstruct the data segment.The access module 80 reconstructs the data object from the data segmentsand the gateway module 78 formats the data object for transmission tothe user device.

FIG. 4 is a schematic block diagram of an embodiment of a grid module 82that includes a control unit 73, a pre-slice manipulator 75, an encoder77, a slicer 79, a post-slice manipulator 81, a pre-slice de-manipulator83, a decoder 85, a de-slicer 87, and/or a post-slice de-manipulator 89.Note that the control unit 73 may be partially or completely external tothe grid module 82. For example, the control unit 73 may be part of thecomputing core at a remote location, part of a user device, part of theDS managing unit 18, or distributed amongst one or more DS storageunits.

In an example of write operation, the pre-slice manipulator 75 receivesa data segment 90-92 and a write instruction from an authorized userdevice. The pre-slice manipulator 75 determines if pre-manipulation ofthe data segment 90-92 is required and, if so, what type. The pre-slicemanipulator 75 may make the determination independently or based oninstructions from the control unit 73, where the determination is basedon a computing system-wide predetermination, a table lookup, vaultparameters associated with the user identification, the type of data,security requirements, available DSN memory, performance requirements,and/or other metadata.

Once a positive determination is made, the pre-slice manipulator 75manipulates the data segment 90-92 in accordance with the type ofmanipulation. For example, the type of manipulation may be compression(e.g., Lempel-Ziv-Welch, Huffman, Golomb, fractal, wavelet, etc.),signatures (e.g., Digital Signature Algorithm (DSA), Elliptic Curve DSA,Secure Hash Algorithm, etc.), watermarking, tagging, encryption (e.g.,Data Encryption Standard, Advanced Encryption Standard, etc.), addingmetadata (e.g., time/date stamping, user information, file type, etc.),cyclic redundancy check (e.g., CRC32), and/or other data manipulationsto produce the pre-manipulated data segment.

The encoder 77 encodes the pre-manipulated data segment 92 using aforward error correction (FEC) encoder (and/or other type of erasurecoding and/or error coding) to produce an encoded data segment 94. Theencoder 77 determines which forward error correction algorithm to usebased on a predetermination associated with the user's vault, a timebased algorithm, user direction, DS managing unit direction, controlunit direction, as a function of the data type, as a function of thedata segment 92 metadata, and/or any other factor to determine algorithmtype. The forward error correction algorithm may be Golay,Multidimensional parity, Reed-Solomon, Hamming, Bose Ray ChauduriHocquenghem (BCH), Cauchy-Reed-Solomon, or any other FEC encoder. Notethat the encoder 77 may use a different encoding algorithm for each datasegment 92, the same encoding algorithm for the data segments 92 of adata object, or a combination thereof.

The encoded data segment 94 is of greater size than the data segment 92by the overhead rate of the encoding algorithm by a factor of X/T, whereX is the width or number of slices, and T is the read threshold. In thisregard, the corresponding decoding process can accommodate at most X-Tmissing EC data slices and still recreate the data segment 92. Forexample, if X=16 and T=10, then the data segment 92 will be recoverableas long as 10 or more EC data slices per segment are not corrupted.

The slicer 79 transforms the encoded data segment 94 into EC data slicesin accordance with the slicing parameter from the vault for this userand/or data segment 92. For example, if the slicing parameter is X=16,then the slicer 79 slices each encoded data segment 94 into 16 encodedslices.

The post-slice manipulator 81 performs, if enabled, post-manipulation onthe encoded slices to produce the EC data slices. If enabled, thepost-slice manipulator 81 determines the type of post-manipulation,which may be based on a computing system-wide predetermination,parameters in the vault for this user, a table lookup, the useridentification, the type of data, security requirements, available DSNmemory, performance requirements, control unit directed, and/or othermetadata. Note that the type of post-slice manipulation may includeslice level compression, signatures, encryption, CRC, addressing,watermarking, tagging, adding metadata, and/or other manipulation toimprove the effectiveness of the computing system.

In an example of a read operation, the post-slice de-manipulator 89receives at least a read threshold number of EC data slices and performsthe inverse function of the post-slice manipulator 81 to produce aplurality of encoded slices. The de-slicer 87 de-slices the encodedslices to produce an encoded data segment 94. The decoder 85 performsthe inverse function of the encoder 77 to recapture the data segment90-92. The pre-slice de-manipulator 83 performs the inverse function ofthe pre-slice manipulator 75 to recapture the data segment 90-92.

FIG. 5 is a diagram of an example of slicing an encoded data segment 94by the slicer 79. In this example, the encoded data segment 94 includesthirty-two bits, but may include more or less bits. The slicer 79disperses the bits of the encoded data segment 94 across the EC dataslices in a pattern as shown. As such, each EC data slice does notinclude consecutive bits of the data segment 94 reducing the impact ofconsecutive bit failures on data recovery. For example, if EC data slice2 (which includes bits 1, 5, 9, 13, 17, 25, and 29) is unavailable(e.g., lost, inaccessible, or corrupted), the data segment can bereconstructed from the other EC data slices (e.g., 1, 3 and 4 for a readthreshold of 3 and a width of 4).

FIG. 6 is a schematic block diagram of another embodiment of a computingsystem. The system includes a user device 14, a dispersed storage (DS)processing unit 16, and a plurality of sites 100, 102. Each site of theplurality of sites 100, 102 may be located at different geographiclocations providing geographic diversity. The sites provide a physicalinstallation environment, required power, and network connectivity(e.g., wireline and/or wireless) to other sites of a dispersed storagenetwork (DSN). Each site of the plurality of sites hosts one or morecontainers of a plurality of containers 108-114 and each site hosts atleast one site controller of a plurality of site controllers 104-106.For each site, the at least one site controller may be implemented as aseparate computing unit (e.g., a server) or as a function within one ormore of the one or more containers.

Each container (e.g., a shipping container, a box, a sealed environment,a tanker, a thermal control pool) of the one or more containers includesone or more of network connectivity, one or more DS units 1-U, at leastone container controller of a plurality of container controllers116-122, environmental control (e.g., heating and cooling), and a powerinput 124. The at least one container controller may be implemented as aseparate computing unit or as a function within the one or more DS units1-U. For example, container 1 108 at site 1 100 includes a containercontroller 1 116 and DS units 1-U associated with container 1 108 andcontainer 2 110 at site 1 100 includes a container controller 2 118 andDS units 1-U associated with container 2 110.

The at least one site controller assists in container operationsassociated with a common site. For example, site controller 1 104receives an access request from DS processing unit 16 and facilitatesaccess to the one or more containers 108-110 associated with sitecontroller 1 104. As another example, site controller 1 104 facilitatesmigration of stored encoded data slices 11 from container 1 108 of site1 100 to container 2 110 of site 1 100 based on migration criteria.

The at least one container controller assists in container operationsassociated with the at least one container controller. For example,container controller 2 122 of container 2 114 of site 2 102 receives anaccess request from DS processing unit 16 and facilitates access to theone or more DS units 1-U associated with the container controller 2 122.As another example, container controller 1 120 of container 1 112 ofsite 2 102 facilitates migration of stored encoded data slices 11 fromDS unit 2 of container 1 112 of site 2 102 to DS unit 10 of container 1112 of site 2 102 based on migration criteria.

In an example of storing data, encoded data slices 11 associated witheach pillar of a pillar width number of a set of encoded data slices arestored within a common container. For instance, the DS processing unit16 dispersed storage error encodes data to produce a plurality of setsof encoded data slices 11, wherein each set of the plurality of sets ofencoded data slices includes four pillars of encoded data slices when apillar width is four. Next, the DS processing unit 16 facilitate storageof each set of four encoded data slices of the plurality of sets ofencoded data slices 11 in DS units 1-4 of container 1 108 at site 1 100.In an example of retrieving the data, the DS processing unit 16facilitates retrieval of at least three encoded data slices 11 from DSunits 1-4 of container 1 108 at site 1 100 when a decode threshold isthree. In an example of rebuilding an encoded data slice of a set of theplurality of sets of encoded data slices, container controller 1 116 atsite 1 100 retrieves at least three encoded data slices 11 from DS units1-4 of container 1 108 at site 1 100 and dispersed storage error decodesthe at least three encoded data slices to reproduce a data segmentassociated with an encoded data slice to be rebuilt. Next, the containercontroller 1 116 at site 1 100 dispersed storage error encodes the datasegment to reproduce the data slice to be rebuilt.

In another example storing data, encoded data slices associated witheach pillar of the pillar with number of the set of encode slices arestored within two or more containers of a common site. For instance, aDS processing unit 16 facilitates storage of two encoded data slices ofeach set of four encoded data slices of the plurality of sets of encodeddata slices 11 in DS units 1-2 of container 1 112 at site 2 102 andfacilitates storage of a remaining two encoded data slices of each setof four encoded data slices of the plurality of sets of encoded dataslices in DS units 1-2 of container 2 114 at site 2 102.

In an example of retrieving the data, the DS processing unit 16facilitates retrieval of at least three encoded data slices 11 from DSunits 1-2 of container 1 112 at site 2 102 and DS units 1-2 of container2 114 at site 2 102. In an example of rebuilding an encoded data sliceof a set of the plurality of sets of encoded data slices 11, sitecontroller 2 106 at site 2 102 retrieves at least three encoded dataslices 11 from DS units 1-2 of container 1 112 at site 2 102 and DSunits 1-2 of container 2 114 at site 2 102 and dispersed storage errordecodes the at least three encoded data slices to reproduce a datasegment associated with an encoded data slice to be rebuilt. Next, thesite controller 2 106 at site 2 102 dispersed storage error encodes thedata segment to reproduce the data slice to be rebuilt.

FIG. 7A is a schematic block diagram of another embodiment of acomputing system that includes a computing device 130 and a maintenancefree storage container 132. The maintenance free storage container 132includes a plurality of storage devices 134. A storage device mayinclude at last one of a memory device, a plurality of memory devices,and a plurality of dispersed storage (DS) units 36. The computing device130 may be implemented as at least one of a site controller, a containercontroller, a user device, a DS processing unit, a DS unit, a DSmanaging unit, and any other computing device operable to couple withthe maintenance free storage container 132. The computing device 130includes a DS module 136. The DS module 136 includes a determine failureinformation module 138, a maintain dynamic container address spacemodule 140, a manage address mapping module 142, and a monitor module144.

The determine failure information module 138, when operable within thecomputing device 130, causes the computing device 130 to determinestorage device failure information 146 for a plurality of storagedevices 134 within the maintenance free storage container 132, whereinthe maintenance free storage container 132 allows for multiple storagedevices 134 of the plurality of storage devices 134 to be in a failuremode without replacement and wherein the storage device failureinformation 146 indicates storage devices 134 of the plurality ofstorage devices 134 that are in the failure mode. The determine failureinformation module 138 functions to determine the storage device failureinformation 146 by determining that one or more storage locations withina first storage device of the plurality of storage devices has failed,determining that a second storage device of the plurality of storagedevices has failed, and determining that a third storage device of theplurality of storage devices is operating at less than a desired storagelevel but greater than a storage failure level. The determine failureinformation module 138, when operable within the computing device 130,further causes the computing device 130 to obtain local storage devicefailure information 148 from a plurality of dispersed storage (DS) unitswithin the maintenance free storage container 132, wherein a DS unit ofthe plurality of DS units includes a set of storage devices 134 of theplurality of storage devices 134 and compile the location storage devicefailure information 148 to determine the storage device failureinformation 146.

The maintain dynamic container address space module 140, when operablewithin the computing device 130, causes the computing device 130 tomaintain a dynamic container address space 150 of the maintenance freestorage container 132 based on the storage device failure information146. The dynamic container address space 150 includes at least one of astorage device (ID), a DS unit ID, a storage device internet protocol(IP) address, a DS unit IP address, and a storage device physicallocation designator. The maintain dynamic container address space module140 functions to maintain the dynamic container address space 150 byidentifying one or more storage locations within a first storage deviceof the plurality of storage devices 134 is in the storage device failureinformation 146 as failed and removing one or more addresses associatedwith the one or more storage locations from the dynamic containeraddress space 150 and identifying a second storage device of theplurality of storage devices is in the storage device failureinformation 146 as failed and removing addresses associated with thesecond storage device from the dynamic container address space 150.Next, the maintain dynamic container address space module 140 identifiesa third storage device of the plurality of storage devices is in thestorage device failure information 146 as being at less than a desiredstorage level, removes one or more addresses associated with failedstorage locations of the third storage device from the dynamic containeraddress space 150, and flags remaining addresses of the third storagedevice in the dynamic container address space 150 as being of reducedreliability.

The manage address mapping module 142, when operable within thecomputing device 130, causes the computing device 130 to manage mapping152 of container addresses of the dynamic container address space 150 todispersed storage network (DSN) addresses of an assigned DSN addressrange 154. The assigned DSN address range 154 may include one or more ofa site ID, a container ID, a storage device ID, a slice name range, astart DSN address, an end DSN address, a start slice name, and an endslice name. The assigned DSN address range 154 may be received from atleast one of a DS managing unit and a DS processing unit. The manageaddress mapping module 142 functions to manage mapping containeraddresses of the dynamic container address space 150 to DSN addressesby, when a write request 156 to an address within the assigned addressrange is received, determining a container address within the dynamiccontainer address space 150 based on the storage device failureinformation 146 and address availability 158 within the dynamiccontainer address space 150, facilitating the write request 156 to thecontainer address, and updating the current address availability 158within the dynamic container address space 150.

The updating the current address availability 158 includes indicatingthat the container address is mapped to the address within the assignedDSN address range 154. The determining the container address includesselecting a storage address associated with a storage device with adesired level of reliability as indicated by the storage device failureinformation 146. The selecting may also include selecting a containeraddress that is associated with storage with a common pillar of DSNaddresses (e.g., select a storage device that is already storing slicesof the same pillar). Selecting may also include selecting a containeraddress that is associated with favorable storage device failureinformation 146 when each address of the dynamic container address space150 is not associated with a pillar number of the DSN address. Selectingmay also include selecting a container address that is associated with aDSN address that is adjacent to the DSN address.

The manage address mapping module 142 further functions to managemapping container addresses of the dynamic container address space toDSN addresses by determining, based on the storage device failureinformation 146, whether a stored encoded data slice is to be rebuilt oris to be moved to a different container address. For example, the manageaddress mapping module 142 determines that the stored encoded data sliceis to be rebuilt when at least one of the slice is stored in a failedstorage location in the slice is stored in a failed storage device. Asanother example, the manage address mapping module 142 determines thatthe stored encoded data slice is to be moved when the stored encodeddata slice is stored in a storage device associated with a reliabilitylevel below a reliability threshold based on the storage device failureinformation.

When the stored encoded data slice is to be rebuilt, the manage addressmapping module 142 rebuilds the stored encoded data slice in accordancewith a dispersed storage error coding function to produce a rebuiltencoded data slice and determines a new container address within thedynamic container address space 150 based on the storage device failureinformation 146 and current address availability 158 within the dynamiccontainer address space 150. The rebuilding includes obtaining a decodethreshold number of encoded data slices associated with a common datasegment of the stored encoded data slice, decoding the decode thresholdnumber of encoded data slices to reproduce the common data segment, andencoding the common data segment to produce the rebuilt encoded dataslice. Next, the manage address mapping module 142 facilitates writingthe rebuilt encoded data slice to the new container address, updatingthe mapping 152 of container addresses to the DSN addresses with the newcontainer address, and updating the current address availability 158within the dynamic container address space 150.

When the stored encoded data slice is to be moved, the manage addressmapping module 142 determines a new container address within the dynamiccontainer address space 150 based on the storage device failureinformation 146 and current address availability 158 within the dynamiccontainer address space 150 and facilitates writing the encoded dataslice to the new container address. Next, the manage address mappingmodule 142 updates the mapping of container addresses to the DSNaddresses with the new container address and updates the current addressavailability 158 within the dynamic container address space 150.

The monitor module 144, when operable within the computing device 130,causes the computing device 130 to monitor the storage device failureinformation 146 and when the storage device failure information 146 isat a container level threshold, generate an indication 160 that themaintenance free storage container 132 is in need of replacement. Themonitor module 144, when operable within the computing device 130,further causes the computing device 130 to monitor the storage devicefailure information 146 and when the storage device failure information146 is at a container level threshold, generate a request 162 to reducethe assigned DSN address range. When the request to reduce the assignedDSN address range is granted (e.g., the manage address mapping module142 and/or the monitor module 144 receives an updated assigned DSNaddress range), the monitor module 144 facilitates writing a selectedgroup of encoded data slices (e.g., corresponding to a reduced portionof the assigned DSN address range) to another maintenance free storagecontainer and adjusts the mapping 152 of the container addresses of thedynamic container address space 150 to the DSN addresses of a reducedDSN address range (e.g., excluding the reduced portion of the assignedDSN address range).

FIG. 7B is a flowchart illustrating an example of assigning a dispersedstorage network (DSN) address range. The method begins at step 170 wherea processing module (e.g., of a site controller, a container controller,a storage device, a dispersed storage (DS) processing unit, a DS unit)determines storage device failure information for a plurality of storagedevices within a maintenance free storage container, wherein themaintenance free storage container allows for multiple storage devicesof the plurality of storage devices to be in a failure mode withoutreplacement and wherein the storage device failure information indicatesstorage devices of the plurality of storage devices that are in thefailure mode. The determining the storage device failure informationincludes determining that one or more storage locations within a firststorage device of the plurality of storage devices has failed,determining that a second storage device of the plurality of storagedevices has failed, and determining that a third storage device of theplurality of storage devices is operating at less than a desired storagelevel but greater than a storage failure level. The determining storagedevice failure information includes obtaining local storage devicefailure information from a plurality of DS units within the maintenancefree storage container, wherein a DS unit of the plurality of DS unitsincludes a set of storage devices of the plurality of storage devicesand compiling the location storage device failure information todetermine the storage device failure information.

The method continues at step 172 where the processing module maintains adynamic container address space of the maintenance free storagecontainer based on the storage device failure information. Themaintaining the dynamic container address space includes identifying oneor more storage locations within a first storage device of the pluralityof storage devices is in the storage device failure information asfailed and removing one or more addresses associated with the one ormore storage locations from the dynamic container address space andidentifying a second storage device of the plurality of storage devicesis in the storage device failure information as failed and removingaddresses associated with the second storage device from the dynamiccontainer address space. The maintaining the dynamic container addressspace further includes identifying a third storage device of theplurality of storage devices is in the storage device failureinformation as being at less than a desired storage level, removing oneor more addresses associated with failed storage locations of the thirdstorage device from the dynamic container address space, and flaggingremaining addresses of the third storage device in the dynamic containeraddress space as being of reduced reliability.

The method continues at step 174 where the processing module managesmapping of container addresses of the dynamic container address space todispersed storage network (DSN) addresses of an assigned DSN addressrange. The managing mapping container addresses of the dynamic containeraddress space to DSN addresses includes, when a write request to anaddress within the assigned address range is received, determining acontainer address within the dynamic container address space based onthe storage device failure information and current address availabilitywithin the dynamic container address space, facilitating the writerequest to the container address, and updating the current addressavailability within the dynamic container address space. Selecting mayalso include selecting a container address that is associated withstorage with a common pillar of DSN addresses (e.g., select a storagedevice that is already storing slices of the same pillar). Selecting mayalso include selecting a container address that is associated withfavorable storage device failure information when each address of thedynamic container address space is not associated with a pillar numberof the DSN address. Selecting may also include selecting a containeraddress that is associated with a DSN address that is adjacent to theDSN address.

The managing mapping container addresses of the dynamic containeraddress space to DSN addresses further includes determining, based onthe storage device failure information, whether a stored encoded dataslice is to be rebuilt or is to be moved to a different containeraddress. When the stored encoded data slice is to be rebuilt, continuingat step 174, the processing module rebuilds the stored encoded dataslice in accordance with a dispersed storage error coding function toproduce a rebuilt encoded data slice and determines a new containeraddress within the dynamic container address space based on the storagedevice failure information and current address availability within thedynamic container address space. Next, the processing module facilitateswriting the rebuilt encoded data slice to the new container address,updates the mapping of container addresses to the DSN addresses with thenew container address, and updates the current address availabilitywithin the dynamic container address space.

When the stored encoded data slice is to be moved, continuing at step174, the processing module determines a new container address within thedynamic container address space based on the storage device failureinformation and current address availability within the dynamiccontainer address space. Next, the processing module facilitates writingthe encoded data slice to the new container address, updates the mappingof container addresses to the DSN addresses with the new containeraddress, and updates the current address availability within the dynamiccontainer address space.

The method continues at step 176 where the processing module monitorsthe storage device failure information. The monitoring includescomparing the storage device failure information to one or morecontainer level thresholds. The one or more container level thresholdsincludes at least one of a failure threshold and a failing threshold.The failure threshold indicates that the maintenance free storagecontainer has reached an end-of-life due to failure. The failingthreshold indicates that at least a portion of the plurality of storagedevices of the maintenance free storage container have failed and thatthe remaining portion of the plurality of storage devices of themaintenance free storage container are operational. When the storagedevice failure information is at the container level failure threshold,the method continues at step 178 where the processing module generatesan indication that the maintenance free storage container is in need ofreplacement. For example, the processing module generates the indicationand outputs the indication to a DS managing unit.

When the storage device failure information is at the container failinglevel threshold, the method continues at step 180 where the processingmodule generates a request to reduce the assigned DSN address range. Thegenerating includes one or more of generating the request, outputtingthe request (e.g., to a DS processing unit), and receiving a response.When the request to reduce the assigned DSN address range is granted,the method continues at step 182 where the processing module facilitateswriting a selected group of encoded data slices to another maintenancefree storage container. The facilitating includes one or more ofselecting the selected group of encoded data slices (e.g., correspondingto storage devices associated with unfavorable storage device failureinformation), retrieving the selected group of encoded data slices fromstorage devices of the maintenance free storage container, selecting theother maintenance free storage container (e.g., associated withfavorable other storage device failure information), and outputting theretrieved selected group of encoded data slices to the selected othermagnets free storage container. The method continues at step 184 wherethe processing module adjusts the mapping of the container addresses ofthe dynamic container address space to DSN addresses of a reduced DSNaddress range. For example, the processing module identifies DSNaddresses excluded from the DSN address range based on the reduced DSNaddress range and eliminates the corresponding mapping for the excludedDSN addresses.

FIG. 8A is a schematic block diagram of another embodiment of acomputing system that includes a storage network 192 and at least onemaintenance free storage container 190. The storage network 192 includesone or more of a dispersed storage (DS) processing unit 16, a rootcertificate authority (CA) 194, a client, a user device, and a DSmanaging unit. The maintenance free storage container 190 includes aplurality of storage servers 1-U, a container controller 196, acontainer CA 198, and a local area network (LAN) 199. Alternatively, twoor more maintenance free storage containers 190 share a common containercontroller 196 and/or a common container CA 198. The container CA 198includes an internal network interface 208 and a processing moduleoperable 218.

Each storage server of the plurality storage servers 1-U includes aplurality of storage devices 200 and a server control module 202,wherein the server control module 202 manages storage and retrieval ofdata 204 from the plurality of storage devices 200, and wherein themaintenance free storage container 190 allows for multiple storageservers of the plurality of storage servers 1-U to be in a failure modewithout replacement and allows for multiple storage devices 200 of theplurality of storage devices 200 of one or more the plurality of storageservers 1-U to be in the failure mode without replacement. Each storagedevice 200 includes one or more memory devices (e.g., a magnetic diskdrive, an optical disk drive, solid-state memory, etc.).

The container controller 196 includes an external network interface 206,the internal network interface 208, and a module 210. The module 210includes a plurality of virtual storage servers 216. Each virtualstorage server of the plurality of virtual storage servers 216 includeshardware and/or software of module 210 to provide a storage server withrespect to the storage network 192, wherein the storage network 192addresses each virtual storage server utilizing one or more dispersedstorage network (DSN) addresses. The DSN address includes a vaultidentifier and a pillar identifier, wherein the vault identifieridentifies a virtual storage vault of a DSN and the pillar identifieridentifies a specific pillar coded value of data encoded using adispersed storage error coding function. For example, virtual storageserver A_1 corresponds to vault A and pillar 1 and virtual storageserver B_2 corresponds to vault B and pillar 2. Each virtual vault ofthe DSN includes a pillar width number of pillars, wherein the pillarwidth corresponds to the vault. For example, vault A includes a pillarwidth of 16 and vault B includes a pillar width of 8.

A number of virtual storage servers per vault are assigned to the module210 in accordance with a storage network storage scheme. For example, afirst 3 pillars of vault B are to be stored in virtual storage serversB_1, B_2, and B_3 of a first container controller 196 of a firstmaintenance free storage container 190 and a remaining 5 pillars ofvault B are to be stored in virtual storage servers of a secondcontainer controller 196 of a second maintenance free storage container190 when the storage network storage scheme includes associating atleast a decode threshold number of pillars with each maintenance freestorage container 190 of at least two maintenance free storagecontainers 190 and the decode threshold is 3 and the pillar width is 8.

The container controller 196 is operable to manage failure modeinformation (e.g., a performance level, a reliability level, anavailability level) of the plurality of storage servers 1-U, managemapping of the plurality of virtual storage servers 216 to at least someof the plurality of storage servers 1-U based on the failure modeinformation. The container controller 196 is further operable tocommunicate, via the external network interface 206, storage serveraccess requests 212 with a device (e.g., the DS processing unit 16)external to the maintenance free storage container 190 using addressingof the plurality of virtual storage servers 216. The containercontroller 196 is further operable to communicate, via the internalnetwork interface 208, the storage server access requests 212 within themaintenance free storage container 190 using addressing of the pluralityof storage servers 1-U (e.g., an Internet protocol address of a storageserver).

The container controller 196 is further operable to facilitateauthentication of the plurality of virtual storage servers 216 with thestorage network root certificate authority 194 utilizing storage networktrust messages 214 via the external network interface 206. The containerCA 198 is operable to authenticate, via the internal network interface208, the plurality of storage servers 1-U to produce a plurality ofstorage server container certificates that are an indication of trustwithin the maintenance free storage container 190. The container CA 198is further operable to authenticate, via the internal network interface208, the plurality of virtual storage servers 216 to produce a pluralityof virtual storage server container certificates that are an indicationof trust within the maintenance free storage container 190.Authentication of the plurality of virtual storage servers 216 andauthentication of the plurality of storage servers 1-U is discussed ingreater detail with reference to FIG. 8B.

The managing of the mapping of the plurality of virtual storage servers216 to the at least some of the plurality of storage servers 1-U furtherincludes accessing a trust table that includes a plurality of entriescorresponding to the plurality of storage servers 1-U, wherein an entryof the plurality of entries includes an indication as to whether astorage server of the plurality of storage servers 1-U in a trustedstate, a temporary untrusted state, or a permanent untrusted state. Thecontainer controller 196 is further operable to update the trust tableby determining that the storage server is in the temporary untrustedstate when the storage server is currently unavailable (e.g., noresponse) and the entry does not indicate that the storage server is inthe permanent untrusted state and determining that the storage server isin the permanent untrusted state when the storage server has failed(e.g., permanently auto service, a failure rate compares unfavorably toa failure threshold) or has been compromised (e.g., at least one storageserver access requests results in data that fails an integrity test).

The container controller 196 is further operable to receive, via theexternal network interface 206, a storage server access request of thestorage server access requests 212, wherein the storage server accessrequest includes a virtual storage server address of a virtual storageserver of the plurality of virtual storage servers 216 and a rootcertificate (e.g., a signed certificate by the root CA 194). Thecontainer controller 196 is further operable to process the storageserver access request by determining whether the root certificate isvalid (e.g., validation is favorable of the root certificate includinguse of a public key associated with the root CA 194), and when the rootcertificate is valid, identifying a storage server of the plurality ofstorage servers 1-U based on the mapping of the plurality of virtualstorage servers to the at least some of the plurality of storage servers1-U. Next, the container controller 196 is further operable to determinetrust status of the identified storage server. The determining truststatus may include one or more of receiving a signed certificate fromthe identified storage server, initiating a re-authentication (e.g.,invoking the identified storage server to issue a certificate signingrequest), and accessing the trust table. When the trust status is apermanent untrusted state, the container controller 196 is furtheroperable to flag the virtual storage server for remapping to a trustedstorage server of the plurality of storage servers 1-U.

When the trust status is a temporary untrusted state, the containercontroller 196 is further operable to respond to the storage serveraccess request as if the storage server is currently unavailable. Theresponding includes at least one of re-triggering an authenticationsequence, ignoring the storage server access request, and sending a notavailable message.

When the trust status is a temporary untrusted state, the containercontroller 196 is further operable to convert an address of the storageserver access request from the addressing of the plurality of virtualstorage servers to the addressing of the plurality of storage servers toproduce a container storage server address and send the convertedstorage server access request to the identified storage server using thecontainer storage server address. The identified storage server converts(e.g. a table lookup) the container storage server address into aphysical address (e.g., memory device identifier, memory offset, memoryblock number) of one or more of the plurality of storage devices withinthe identified storage server.

The container controller 196 is further operable to manage mapping ofthe plurality of virtual storage servers 216 to at least some of theplurality of storage servers by 1-U interpreting the failure modeinformation to identify a failed storage server of the plurality ofstorage servers 1-U, utilizing a dispersed storage error coding functionto rebuild data stored in the failed storage server to produce rebuiltdata, and storing the rebuilt data in another storage server of theplurality of storage servers 1-U. The rebuilding includes retrieving oneor more sets of at least a decode threshold number of encoded dataslices of one or more common data segments corresponding to data to berebuilt, decoding the one or more sets of the at least the decodethreshold number of encoded data slices utilizing the dispersed storageerror coding function to produce one or more reproduced common datasegments, and encoding the one or more reproduced common data segmentsutilizing the dispersed storage error coding function to produce therebuilt data. Alternatively, the container controller 196 is furtheroperable to send a rebuild data request that includes identity of thedata to be rebuilt to at least one of another container controller 196,a storage server, the DS processing unit 16, and a storage network 192.

The container controller 196 is further operable to manage mapping ofthe plurality of virtual storage servers to at least some of theplurality of storage servers by interpreting the failure modeinformation to identify a failed storage device of a storage server ofthe plurality of storage servers, utilizing a dispersed storage errorcoding function to rebuild data stored in the failed storage device toproduce rebuilt data, and storing the rebuilt data in another storagedevice in the storage server or in another storage server of theplurality of storage servers 216.

FIG. 8B is a schematic block diagram of an embodiment of anauthentication system that includes a dispersed storage (DS) processingunit 16, a root certificate authority (CA) 194, a virtual storage serverB_2 216 (e.g., associated with a vault B and a pillar 2), a container CA198, and a storage server 1. The authentication system is operable toauthenticate the DS processing unit 16 and the virtual storage serverB_2 216 with the root certificate authority 194, to authenticate thevirtual storage server B_2 216 and the storage server 1 with thecontainer certificate authority 198, and to generate an updated storageserver trust table 236. Authentication includes a requesting entitygenerating a certificate signing request, the requesting entity sendingthe certificate signing request to a corresponding certificateauthority, the corresponding certificate authority validating thecertificate signing request, the corresponding certificate authoritygenerating a signed certificate, the corresponding certificate authoritysending the signed certificate to the requesting entity, the requestingentity receiving the signed certificate, and the requesting entitysaving the signed certificate for subsequent utilization.

The certificate signing request includes one or more of a requestingentity universally unique identifier (UUID), a requesting entity publickey, a requesting entity authorization code, and a signature over atleast a portion of the certificate signing request generated by therequesting entity utilizing a requesting entity private key. Thesignature may include utilization of a signature algorithm andencrypting a hash digest of the least the portion of the certificatesigning request, wherein the encrypting utilizes the requesting entityprivate key. The requesting entity private key may be generated by therequesting entity based on a random number. The requesting entity publickey may be generated based on the requesting entity private key and inaccordance a public key infrastructure (PKI) function.

The validating of the certificate signing request includes one or moreof determining whether a received authentication code and received UUIDcompare favorably to a list of authorized pairs of authentication codesand UUIDs and determining whether the signature of the requesting entityis valid. The corresponding certificate authority indicates that thecertificate signing request is not valid when the receivedauthentication code and received UUID do not match an authorized pair ofauthentication codes and UUIDs. The determining whether the signature ofthe requesting entity is valid includes at least one of utilizing avalidation algorithm associated with a signature type and determiningwhether a calculated hash digest of the at least the portion of thereceived certificate signing request compares favorably to a decryptedsignature utilizing the requesting entity public key. The correspondingcertificate authority indicates that the certificate signing request isnot valid when the calculated hash digest of the at least the portion ofthe received certificate signing request is not substantially the sameas the decrypted signature. The corresponding certificate authorityindicates that the certificate signing request is valid when thecorresponding certificate authority does not indicate that thecertificate signing request is invalid. The corresponding certificateauthority saves one or more of the UUID other requesting entity and thepublic key of the requesting entity.

The corresponding certificate authority generates the signed certificateto include a corresponding certificate authority public key, acertificate timeout indicator, and a signed certificate signature. Thegenerating of the signed certificate signature includes generating thesigned certificate signature, utilizing a corresponding certificateauthority private key, over one or more of at least a portion of thecertificate signing request and an ordered certificate chain thatincludes one or more other signed certificates (e.g., order from thecorresponding certificate authority up to an associated highest ordercertificate authority if any). The signature generation may include oneor more of utilizing a signature algorithm and encrypting a hash digestof the least the portion of an item to be signed, wherein the encryptingutilizes the corresponding certificate authority private key. Thecorresponding certificate authority private key may be generated by thecorresponding certificate authority based on a random number. Thecorresponding certificate authority public key may be generated based onthe corresponding certificate authority private key and in accordancethe PKI function.

The requesting entity may initiate authentication with the correspondingcertificate authority based on at least one of detecting newinstallation, detecting a reset, receiving an error message, receiving arequest to re-authenticate, and detecting a previous signed certificatetimeout. Initiating authentication includes generating the certificatesigning request and sending the certificate signing request to thecorresponding certificate authority. The corresponding certificateauthority completes authentication by validating the certificate signingrequest, generating a signed certificate, and sending the signedcertificate to the requesting entity.

In an example of authentication, DS processing unit 16 generatescertificate signing request 220 to include one or more of a UUIDassociated with DS processing unit 16, an authentication code associatedwith DS processing unit 16, a public key associated with DS processingunit 16, and a signature over at least a portion of the certificatesigning request 220 (e.g., utilizing a private key of the DS processingunit 16). Next, DS processing unit 16 sends the certificate signingrequest 220 to the root certificate authority 194. The root certificateauthority 194 validates certificate signing request 220. When thecertificate signing request 220 is valid, the root certificate authority194 generates a signed certificate 222 to include one or more of apublic key of root certificate authority 194, a certificate timeoutindicator (e.g., 1 day), and a signed certificate signature over atleast a portion of the signed certificate 222 (e.g., utilizing a privatekey of the root certificate authority 194). The DS processing unit 16saves the signed certificate 222 and utilizes the signed certificate 222in at least one subsequent access request with at least one other entityassociated with the root certificate authority 194 (e.g., virtualstorage server B_2 216 of a plurality of virtual storage servers).

In another example of authentication, virtual storage server B_2 216generates certificate signing request 224 to include one or more of aUUID associated with virtual storage server B_2 216, an authenticationcode associated with virtual storage server B_2 216, a public keyassociated with virtual storage server B_2 216, and a signature over atleast a portion of the certificate signing request 224 (e.g., utilizinga private key of the virtual storage server B_2 216). Each virtualstorage server 216 of the plurality of virtual storage servers 216 maybe associated with a unique UUID and a unique authentication code evenwhen two or more virtual storage servers 216 of the plurality of virtualstorage servers 216 may be implemented with a common computing device.Next, virtual storage server B_2 216 sends the certificate signingrequest 224 to the root certificate authority 194. The root certificateauthority 194 validates certificate signing request 224. When thecertificate signing request 224 is valid, the root certificate authority194 generates a signed certificate 226 to include one or more of apublic key of root certificate authority 194, a certificate timeoutindicator (e.g., 1 day), and a signed certificate signature over atleast a portion of the signed certificate 226 (e.g., utilizing a privatekey of the root certificate authority 194). The virtual storage serverB_2 216 saves the signed certificate 226 and utilizes the signedcertificate 226 in at least one subsequent access request with at leastone other entity associated with the root certificate authority 194(e.g., DS processing unit 16).

In yet another example of authentication, virtual storage server B_2 216generates certificate signing request 228 to include one or more of asecond UUID associated with virtual storage server B_2 216, a secondauthentication code associated with virtual storage server B_2 216, asecond public key associated with virtual storage server B_2 216, and asignature over at least a portion of the certificate signing request 228(e.g., utilizing a second private key of the virtual storage server B_2216). Each virtual storage server 216 of the plurality of virtualstorage servers 216 may be associated with a unique second UUID and aunique second authentication code even when two or more virtual storageservers 216 of the plurality of virtual storage servers 216 may beimplemented with a common computing device. The second UUID and thesecond authentication code may be substantially the same as the UUID andthe authentication code. The second public key and the second privatekey may be substantially the same as the public key and the private key.Next, virtual storage server B_2 216 sends the certificate signingrequest 228 to the container certificate authority 198. The containercertificate authority 198 validates certificate signing request 228.When the certificate signing request 228 is valid, the containercertificate authority 198 generates a signed certificate 230 to includeone or more of a public key of container certificate authority 198, acertificate timeout indicator (e.g., 7 days), and a signed certificatesignature over at least a portion of the signed certificate 230 (e.g.,utilizing a private key of the container certificate authority 198). Thevirtual storage server B_2 216 saves the signed certificate 230 andutilizes the signed certificate 230 in at least one subsequent accessrequest with at least one other entity associated with the containercertificate authority 198 (e.g., storage server 1 of a plurality ofstorage servers 1-U).

In a still further example of authentication, storage server 1 generatescertificate signing request 232 to include one or more of a UUIDassociated with storage server 1, an authentication code associated withstorage server 1, a public key associated with storage server 1, and asignature over at least a portion of the certificate signing request 232(e.g., utilizing a private key of the storage server 1). Next, thestorage server 1 sends the certificate signing request 232 to thecontainer certificate authority 198. The container certificate authority198 validates certificate signing request 232. The validation includesindicating that the certificate signing request 232 is not valid when anentry on the updated storage server trust table 236 indicates that thestorage server 1 is associated with a trust status of permanentlyuntrusted. When the certificate signing request 232 is valid, thecontainer certificate authority 198 generates a signed certificate 234to include one or more of the public key of container certificateauthority 198, a certificate timeout indicator (e.g., 7 days), and asigned certificate signature over at least a portion of the signedcertificate 234 (e.g., utilizing the private key of the containercertificate authority 198). The generating the signed certificate 234includes updating the updated storage trust table 236 to indicate thatstorage server 1 is associated with a trust status of trusted. Theupdating includes sending the updated storage trust table 236 to one ormore of at least one container controller and one or more of theplurality of virtual storage servers 216. The storage server 1 saves thesigned certificate 234 and utilizes the signed certificate 234 in atleast one subsequent access request and/or response with at least oneother entity associated with the container certificate authority 198(e.g., virtual storage server B_2 216).

FIG. 8C is a flowchart illustrating an example of processing a storageserver access request. The method begins at step 240 where theprocessing module (e.g., of a container controller) receives a storageserver access request, wherein the storage server access requestincludes a virtual storage server address of a virtual storage server ofa plurality of virtual storage servers and a root certificate (e.g., arequesting entity root certificate authority signed certificate. Themethod continues at step 242 where the processing module determineswhether the root certificate is valid. The method branches to step 246when the processing module determines that the root certificate isvalid. The method continues to step 244 when the processing moduledetermines that the root certificate is not valid. The method continuesat step 244 where the processing module indicates that the storageserver access request and/or the root certificate is not valid. Theindicating includes at least one of setting a flag, sending an errormessage, and sending a message to the requesting entity, wherein themessage includes an indication that the storage server access requestand/or the root certificate is not valid.

When the root certificate is valid, the method continues at step 246where the processing module identifies a storage server of a pluralityof storage servers based on a mapping of the plurality of virtualstorage servers to the at least some of the plurality of storageservers. The method continues at step 248 where the processing moduledetermines trust status of the identified storage server. Thedetermining includes at least one of sending a request forre-authentication to the identified storage server, receiving an updatedtrust status based on a re-authentication response (e.g., received fromat least one of the identified storage server and a containercertificate authority), and accessing a trust table.

When the trust status is a permanent untrusted state, the methodcontinues at step 250 where the processing module flags the virtualstorage server for remapping to a trusted storage server of theplurality of storage servers. The remapping may subsequently invokerebuilding or transfer of slices from the identified storage server tothe trusted storage server.

When the trust status is a temporary untrusted state, the methodcontinues at step 252 where the processing module responds to thestorage server access request as if the storage server is currentlyunavailable. The responding includes at least one of sending the requestfor re-authentication to the identified storage server, outputting astorage server access response to the requesting entity that indicatesthat the storage server is not available, and allowing the storageserver access request to timeout (e.g., ignore the request).

When the trust status of the identified storage server is trusted, themethod continues at step 254 where the processing module enables access.The enabling includes at least one of sending the storage server accessrequest to the identified storage server and converting the storageserver access request. The processing module converts an address of thestorage server access request from addressing of the plurality ofvirtual storage servers to addressing of the plurality of storageservers to produce a container storage server address.

When converting the storage server access request to enable access, themethod continues at step 256 where the processing module sends theconverted storage server access request to the identified storage serverusing the container storage server address such that identified storageserver converts the container storage address into a physical address ofone or more of a plurality of storage devices within the identifiedstorage server, generates a storage server access response (e.g., toinclude an indicator of trust), and outputs the storage server accessresponse. When converting the storage server access request to enableaccess, the method continues at step 258 where the processing module,while the trust status is trusted (e.g., the indicator of trust isvalidated), forwards a received storage server access response to therequesting entity.

FIG. 9A is a schematic block diagram of another embodiment of acomputing system that includes a dispersed storage (DS) processing 34, aset of servers A1-A4, and at least one maintenance free storagecontainer 190. The maintenance free storage container 190 includes aplurality of storage servers 1-U, a container controller 196, and alocal area network (LAN) 199. The servers A1-A4 include one or more of asite controller, a container controller 196, a DS processing unit 16, auser device, a server module, a virtual storage server, and a computingserver.

Each storage server of the plurality storage servers 1-U includes aplurality of storage devices 200 and a server control module 202,wherein the server control module 202 manages storage and retrieval ofdata 204 from the plurality of storage devices 200, and wherein themaintenance free storage container 190 allows for multiple storageservers of the plurality of storage servers 1-U to be in a failure modewithout replacement and allows for multiple storage devices 200 of theplurality of storage devices 200 of one or more the plurality of storageservers 1-U to be in the failure mode without replacement. Each storagedevice 200 includes one or more memory devices (e.g., a magnetic diskdrive, an optical disk drive, solid-state memory, etc.).

The container controller 196 includes an external network interface 206,an internal network interface 208, and a module 210. The module 210includes a plurality of virtual storage servers 216. Each virtualstorage server of the plurality of virtual storage servers 216 includeshardware and/or software of module 210 to provide a storage server withrespect to the DS processing unit for, wherein the DS processing 34accesses each virtual storage server utilizing one or more dispersedstorage network (DSN) addresses via one or more of the servers A1-A4.Alternatively, the DS processing unit 34 directly accesses the virtualstorage servers 216 of the container controller 196. Alternatively,another set of servers such as the servers A1-A4 are implementedresulting in a sequential access through two sets of servers between theDS processing unit 34 and the container controller 196.

The DSN address includes a vault identifier and a pillar identifier,wherein the vault identifier identifies a virtual storage vault of a DSNand the pillar identifier identifies a specific pillar coded value ofdata encoded using a dispersed storage error coding function. Forexample, the container controller 196 includes a first virtual storageserver corresponding to vault 1 and pillar 1 for all of an address rangeassociated with vault 1 and pillar 1, a second virtual storage servercorresponding to vault 1 and pillar 2 for all of an address rangeassociated with vault 1 and pillar 2, a third virtual storage servercorresponding to vault 1 and pillar 3 for all of an address rangeassociated with vault 1 and pillar 3, a fourth virtual storage servercorresponding to vault 1 and pillar 4 for all of an address rangeassociated with vault 1 and pillar 4, a fifth virtual storage servercorresponding to vault 1 and pillar 5 for all of an address rangeassociated with vault 1 and pillar 5, a sixth virtual storage servercorresponding to vault 1 and pillar 6 for all of an address rangeassociated with vault 1 and pillar 6, a seventh virtual storage servercorresponding to vault 1 and pillar 7 for all of an address rangeassociated with vault 1 and pillar 2, and an eighth virtual storageserver corresponding to vault 1 and pillar 2 for all of an address rangeassociated with vault 1 and pillar 8 when vault 1 is associated with apillar width of 8.

The container controller 196 is operable to establish, based on vaultregistry information, a first mapping of a plurality of virtual storageservers 216 of a vault to at least some of the plurality of storageservers 1-U based on storage server utilization information and storageserver failure information. Vault registry information includes, foreach vault of the plurality of vaults, one or more of a vault identifier(ID), a pillar width number, a decode threshold number, and data storageadjustment criteria. The storage server utilization information includesone or more of a storage device utilization level, a storage serverutilization level, and a vault utilization level. The storage serverutilization information may be obtained by one or more of obtainingutilization statistics, initiating a query, receiving test results,accessing historic performance records, a comparison of utilizationinformation to one or more utilization thresholds, and receiving anerror message receiving the storage server utilization information. Thestorage server failure information includes one or more of a failureindicator associated with a storage server, an availability level of thestorage server, a reliability level of the storage server, and aperformance level of the storage server. For example, virtual storageservers for vault 1 pillars 1-8 are established and an entire DSNaddress range corresponding to each pillar is mapped to storage servers1-8 when the pillar width number is 8 and storage server failureinformation associated with storage servers 1-8 is favorable.

The container controller 196 is further operable to facilitate storageof encoded data slices in the at least some of the plurality of storageservers 1-U in accordance with the first mapping. The encoded dataslices include data encoded into the encoded data slices in accordancewith a dispersed storage error coding function. In an example ofoperation, DS processing 34 generates a set of access requests 262-268for a set of slices at a fifth address within each of 8 ranges of slicenames corresponding to 8 pillars of vault 1 utilizing a slice name tonext location table 260. The DS processing 34 utilizes the slice name tonext location table 260 to identify a next server identifier (ID) and anext server internet protocol address(IP) corresponding to the nextserver to send each request of the set of access requests 262-268 basedon a slice name of each request. The slice name to next location table260 includes a plurality of table entries, wherein each table entrycorresponds to a vault and a pillar of the vault. Each table entry ofthe plurality of table entries includes a slice name range field 276, anext server ID field 278, and a next server IP address 280. The slicename range field 276 includes a slice name range entry identifying andassociated vault, pillar, and range of slice names where the vault andpillar are fixed. The next server ID field 278 includes a next server IDentry corresponding to the table entry and an ID of a target server tosend a request and/or message. The next server IP address field 280includes a next server IP address entry corresponding to the table entryand an IP address of the target server to send the request and/ormessage. Structure of the slice name to next location table 260 may beutilized by a first layer of modules and/or system elementscommunicating to a next layer of modules and/or system elements suchthat a routing IP address is identified based on a slice name.

In the example of operation continued, the DS processing 34 sends theset of access requests 262-268 to next server IP addresses (e.g. toservers A1-A4), extracted from slice name to next location table 260based on utilizing slice names as an index into the slice name rangefield 276. Next, each server of the set of servers A1-A4 utilizes slicename to next location table 270 to determine a next server IP address toforward the requests based on utilizing the slice names as an index intothe slice name range field 276 of the slice name to next location table270. Such a forwarded request 272 includes an IP address associated withthe container controller 196. Each virtual storage server of theplurality of stored servers utilizes yet another slice name to nextlocation table to identify storage server IDs and storage server IPaddresses that are mapped utilizing the first mapping to the slicenames. Such another slice name to next location table is discussed ingreater detail with reference to FIGS. 9C-9E. Next, each virtual storageserver forwards the set of requests to the identified storage serversutilizing the storage server IP addresses and including the storageserver IDs.

FIG. 9B is a schematic block diagram of an embodiment of a maintenancefree storage container 190 that includes a container controller 196, alocal area network (LAN) 199, and a set of storage servers 1-8. Thecontainer controller 196 includes a set of virtual storage servers foreach pillar 1-8 associated with a vault 1 when vault 1 utilizes a pillarwidth of 8. Each storage server of the set of storage servers 1-8 isassociated with a unique internet protocol (IP) address to facilitatecommunications with one or more of the container controller 196 and theset of storage servers 1-8 via the LAN 199. For example, storage server2 utilizes an IP address of 24.2 and the container controller 196utilizes an IP address of 33.2. As such, each virtual storage server ofthe set of virtual storage servers may receive and send messagesutilizing the IP address of 33.2. Further addressing may be provided byan identifier associated with each one of the virtual storage servers.

FIG. 9C is a table illustrating an example of a slice name to nextlocation table 274 that includes a plurality of table entries, whereineach table entry of the plurality of table entries includes a slice namerange field 276, a next server identifier (ID) field 278, and a nextserver internet protocol (IP) address field 280. The slice name to nextlocation table 274 may be utilized as a first mapping of a set ofvirtual storage servers of a vault 1 to a set of storage servers 1-8.The set of storage servers includes identifiers of SS1-SS8 andcorresponding IP addresses of 24.1-24.8. For example, all addresses of afourth pillar of vault 1 are mapped to storage server 4 in accordancewith the first mapping.

In example of operation, a virtual storage server receives a sliceaccess request that includes a slice name. The virtual storage servermatches a slice name range entry of the slice name to next locationtable 274 corresponding to the slice name to produce a table entry andextracts a store server ID and next server IP address from the tableentry. Next, the virtual store server forwards the slice access requestto the identified storage server utilizing the extracted next server IPaddress and including the extracted next server ID.

With such a first matching, a high level of reliability may be providedfor storage of encoded data slices of the storage servers when favorablestorage server utilization prevails to provide storage facilities forall pillars. The storage server utilization may increase as more data isstored in the set of storage servers. A container controller associatedwith the set of virtual storage servers may modify the first mapping toproduce a second mapping when the storage server utilization becomesunfavorable. Such a modification of mapping is discussed in greaterdetail with reference to FIGS. 9D-9E.

FIG. 9D is a table illustrating another example of a slice name to nextlocation table 282 that includes a plurality of table entries, whereineach table entry of the plurality of table entries includes a slice namerange field 276, a next server identifier (ID) field 278, and a nextserver internet protocol (IP) address field 280. The slice name to nextlocation table 282 may be utilized as a second mapping of a plurality ofvirtual storage servers of a vault 1 to at least some of a plurality ofstorage servers 1-8. A container controller associated with the set ofvirtual storage servers may modify a first mapping (e.g., as discussedwith reference to FIG. 9C) to produce and utilize the second mapping.The container controller is operable to when, in light of data storageadjustment criteria of vault registry information, evaluation of storageserver utilization information and the storage server failureinformation triggers an adjustment of the first mapping, adjust thefirst mapping in accordance with data storage adjustment criteria toproduce the second mapping the plurality of virtual storage servers ofthe vault to the at least some of the plurality of storage servers. Thedata storage adjustment criteria includes, for the vault, one or more ofa minimum data reliability requirement, a reliability requirementcorresponding to a level of storage capacity utilization, and a maximumstorage capacity utilization level.

The container controller is further operable to adjust the first mappingby reassigning a portion of a dispersed storage network (DSN) addressrange assigned to a first storage server of the plurality of storageservers to a second storage server of the plurality of storage servers.The reassigning includes interpreting the storage server utilizationinformation to identify the first storage server. For example, the firststorage server is identified based on detecting a vault utilizationlevel that is greater than a vault utilization level threshold. Asanother example, the first storage server is identified based ondetecting that transfer of slices can remedy an issue with anotherpillar where not enough encoded data slices are stored (e.g., higherorder the encoded data slices beyond a decode threshold number). Thereassigning further includes identifying a virtual storage serverassociated with the storage server for remapping and identifying theportion of the DSN address range associated with the virtual storageserver for remapping based on the storage server utilizationinformation; (e.g., portion of DSN address associated with slices totransfer). The reassigning further includes selecting the second storageserver for the mapping adjustment based on one or more of the storageserver utilization information, a current mapping of the first storageserver and the portion of the DSN address range. For example, the secondstorage server is selected when the second store has storage capacity toaccommodate receiving encoded data slices corresponding to the portionof the DSN address range. The reassigning further includes updating thevirtual storage server mapping to exclude an association of the portionof the DSN address range with the first storage server and to include anassociation of the portion of the DSN address range with the secondstorage server.

In an example of operation, when the storage server utilizationinformation is unfavorable, the container controller maps 75% of a slicename range corresponding to pillar 1 of vault 1 from storage server 1 tostorage server 1, remaps a remaining 25% of the slice name rangecorresponding to pillar 1 of vault 1 from storage server 1 to storageserver 5, maps 75% of a slice name range corresponding to pillar 2 ofvault 1 from storage server 2 to storage server 2, remaps a remaining25% of the slice name range corresponding to pillar 2 of vault 1 fromstorage server 2 to storage server 6, maps 75% of a slice name rangecorresponding to pillar 3 of vault 1 from storage server 3 to storageserver 3, remaps a remaining 25% of the slice name range correspondingto pillar 3 of vault 1 from storage server 3 to storage server 7, maps75% of a slice name range corresponding to pillar 4 of vault 1 fromstorage server 4 to storage server 4, remaps a remaining 25% of theslice name range corresponding to pillar 4 of vault 1 from storageserver 4 to storage server 8 to produce a portion of the second mappingwhen a pillar width is 8, a decode threshold is 4, and data storageadjustment criteria requires continuing to store 100% of slicesassociated with 100% of address ranges associated with pillars 1-4.

In the example of operation continued, the container controller maps 50%of a slice name range corresponding to pillar 5 of vault 1 from storageserver 5 to storage server 5, remaps a remaining 50% of the slice namerange corresponding to pillar 5 of vault 1 from storage server 5 tostorage server 6, maps 50% of a slice name range corresponding to pillar6 of vault 1 from storage server 6 to storage server 6, and remaps aremaining 50% of the slice name range corresponding to pillar 6 of vault1 from storage server 6 to storage server 8 to produce a remainingportion of the second mapping when a pillar width is 8, a decodethreshold is 4, and the data storage adjustment criteria enablesdiscarding of two pillars of higher order error encoded slices. As such,virtual storage servers associated with pillars 7 and 8 are no longermapped to storage servers within the second mapping. The containercontroller is further operable to facilitate storage of new encoded dataslices in the at least some of the plurality of storage servers based onthe second mapping.

The container controller is operable to facilitate modification ofstorage of the encoded data slices stored in accordance with the firstmapping based on the data storage adjustment criteria. The containercontroller is further operable to facilitate modification of storage ofthe encoded data slices by identifying encoded data slices of theencoded data slices stored in accordance with the first mapping fortransfer from a first storage server of the plurality of storage serversto a second storage server of the plurality of storage servers toproduce identified encoded data slices, facilitating transfer of theidentified encoded data slices to the second storage server, andupdating the storage server utilization information in accordance withthe transferring of the identified encoded data slices. For example, thecontainer controller transfers slices associated with the 25% of theslice name address range of pillar one of vault 1 from storage server 1to storage server 5.

The container controller is further operable to facilitate modificationof storage of the encoded data slices by identifying encoded data slicesof the encoded data slices stored in accordance with the first mappingfor overwriting and updating the storage server utilization informationin accordance with the overwriting of the identified encoded dataslices. The container controller is further operable to facilitatemodification of storage of the encoded data slices by modifyingparameters of a dispersed storage coding function based on the datastorage adjustment criteria to produce modified parameters andfacilitating modification of storage of the encoded data slicesutilizing the modified parameters. For example, the container controllerincreases the pillar width from 8 to 16 when a lowered favorable storageserver utilization is detected. As another example, the containercontroller decreases the pillar width from 8 to 6 when a higherunfavorable storage server utilization is detected.

The container controller is further operable to establish, based onsecond vault registry information (e.g., for another vault), a thirdmapping of a second plurality of virtual storage servers of a secondvault to a second at least some of the plurality of storage serversbased on the storage server utilization information and the storageserver failure information and facilitate storage of second encoded dataslices in the second at least some of the plurality of storage serversin accordance with the third mapping. The container controller isfurther operable to when, in light of second data storage adjustmentcriteria of the second vault registry information, evaluation of thestorage server utilization information and the storage server failureinformation triggers an adjustment of the third mapping, adjust thethird mapping in accordance with the second data storage adjustmentcriteria to produce a fourth mapping the second plurality of virtualstorage servers of the vault to the second at least some of theplurality of storage servers. The container controller is furtheroperable to facilitate storage of new second encoded data slices in thesecond at least some of the plurality of storage servers based on thefourth mapping and facilitate modification of storage of the secondencoded data slices stored in accordance with the third mapping based onthe second data storage adjustment criteria.

FIG. 9E is a table illustrating another example of a slice name to nextlocation table 284 that includes a plurality of table entries, whereineach table entry of the plurality of table entries includes a slice namerange field 276, a next server identifier (ID) field 278, and a nextserver internet protocol (IP) address field 280. The slice name to nextlocation table 284 may be utilized as a third mapping of a plurality ofvirtual storage servers of a vault 1 to at least some of a plurality ofstorage servers 1-8. A container controller associated with the set ofvirtual storage servers may modify a second mapping (e.g., as discussedwith reference to FIG. 9D) to produce and utilize the third mapping. Thecontainer controller is operable to when, in light of data storageadjustment criteria of vault registry information, evaluation of storageserver utilization information and storage server failure informationtriggers an adjustment of the second mapping, adjust the second mappingin accordance with data storage adjustment criteria to produce the thirdmapping the plurality of virtual storage servers of the vault to the atleast some of the plurality of storage servers.

In an example of operation, when the storage server utilizationinformation is unfavorable, the container controller maps 50% of a slicename range corresponding to pillar 1 of vault 1 from storage server 1 tostorage server 1, remaps a remaining 50% of the slice name rangecorresponding to pillar 1 of vault 1 from storage servers 1 and 5 tostorage server 5, maps 50% of a slice name range corresponding to pillar2 of vault 1 from storage server 2 to storage server 2, remaps aremaining 50% of the slice name range corresponding to pillar 2 of vault1 from storage servers 2 and 6 to storage server 6, maps 50% of a slicename range corresponding to pillar 3 of vault 1 from storage server 3 tostorage server 3, remaps a remaining 50% of the slice name rangecorresponding to pillar 3 of vault 1 from storage servers 3 and 7 tostorage server 7, maps 50% of a slice name range corresponding to pillar4 of vault 1 from storage server 4 to storage server 4, remaps aremaining 50% of the slice name range corresponding to pillar 4 of vault1 from storage servers 4 and 8 to storage server 8 to produce a portionof the third mapping when a pillar width is 8, a decode threshold is 4,and data storage adjustment criteria requires continuing to store 100%of slices associated with 100% of address ranges associated with pillars1-4.

In the example of operation continued, the container controller excludesmapping a slice name range corresponding to pillars 5, 6, 7, and 8 ofvault 1 to any storage server to produce a remaining portion of thethird mapping when a pillar width is 8, a decode threshold is 4, and thedata storage adjustment criteria enables discarding of up to 4 pillarsof higher order error encoded slices when the storage server utilizationinformation is unfavorable and creating desired storage capacityrequires elimination of storing encoded data slices of all but a decodethreshold number of pillars. As such, virtual storage servers associatedwith pillars 5-8 are no longer mapped to storage servers within thethird mapping. The container controller is further operable tofacilitate storage of new encoded data slices in the at least some ofthe plurality of storage servers based on the third mapping.

The container controller is further operable to facilitate modificationof storage of the encoded data slices by identifying encoded data slicesof the encoded data slices stored in accordance with the first mappingfor transfer to another maintenance free storage container to produceidentified encoded data slices, facilitating transfer of the identifiedencoded data slices to the other maintenance free storage container, andupdating the storage server utilization information in accordance withthe transferring of the identified encoded data slices. For example, thecontainer controller selects the identified encoded data slices that areassociated with vaults that are associated with an unfavorably highstorage server utilization level, sends the identified encoded dataslices to the other maintenance free storage container, receives astorage confirmation from the other maintenance free storage container,and deletes the identified encoded data slices. Transfer of encoded dataslices from a maintenance free storage container to another maintenancefree storage container is discussed in greater detail with reference toFIGS. 9F-9I.

FIG. 9F is a schematic block diagram of another embodiment of acomputing system that includes a dispersed storage (DS) processing 34, aset of servers A1-A4, and two or more maintenance free storagecontainers 1-2 190. Each maintenance free storage container 190 includesa plurality of storage servers 1-U, a container controller 196, and alocal area network (LAN) 199. The servers A1-A4 include one or more of asite controller, a container controller 196, a DS processing unit 16, auser device, a server module, and a computing server.

The container controller 196 includes plurality of virtual storageservers. The container controller 196 is operable to assign a dispersedstorage network (DSN) address range to each virtual storage server andfor each virtual storage server, map the DSN address range to at leastsome of the plurality of storage serves in accordance with a mapping.For example, the container controller 196 of maintenance free storagecontainer 1 190 modifies a second mapping of virtual storage servers ofmaintenance free storage container 1 190 to produce a third mapping thatincludes mapping of the virtual storage servers of maintenance freestorage container 1 190 to storage servers 1-8 of maintenance freestorage container 1 190 and includes mapping of the virtual storageservers of maintenance free storage container 2 190 to storage servers1-8 of maintenance free storage container 2 190 when maintenance freestorage container 2 190 is added to the computing system.

The container controller 196 of maintenance free storage container 1 190may produce the third mapping in accordance with data storage adjustmentcriteria indicating how to reassign the DSN address ranges associatedwith each pillar when an additional maintenance free storage container 2190 is added to the computing system. The container controller 196determines the third mapping such that the DSN address ranges associatedwith each pillar are split such that each virtual storage serverincludes 50% of the pillar slice name range when the data storageadjustment criteria indicates to split each pillar between eachmaintenance free storage container. For example, a first 50% of slicename ranges associated with vault 1 pillar 1 are associated with avirtual storage server of the maintenance free storage container 1 190and a remaining 50% of slice name ranges associated with vault 1 pillar1 are associated with a virtual storage server of the maintenance freestorage container 2 190. Transitioning from the second mapping to thethird mapping is discussed in greater detail with reference to FIGS. 9Gand 9H.

FIG. 9G is a table illustrating another example of a slice name to nextlocation table 282 as a second mapping associated with a maintenancefree storage container 1 as previously discussed with reference to FIG.9D. The second mapping is transition to a third mapping when amaintenance free storage container 2 is added to store encoded dataslices that were previously only stored in maintenance free storagecontainer 1. The third mapping is discussed in greater detail withreference to FIG. 9H.

FIG. 9H includes tables illustrating more examples of slice name to nextlocation tables 288 and 290 as a third mapping associated with amaintenance free storage container 1 and a maintenance free storagecontainer 2 after transitioning from a second mapping that only includedthe maintenance free storage container 1. A container controllerproduces the third mapping in accordance with data storage adjustmentcriteria indicating how to reassign dispersed storage network (DSN)address ranges associated with each pillar when the additionalmaintenance free storage container 2 is added to the maintenance freestorage container 1. The container controller determines the thirdmapping such that the DSN address ranges associated with each pillar aresplit such that each virtual storage server includes 50% of the pillarslice name range when the data storage adjustment criteria indicates tosplit each pillar between each maintenance free storage container. Forexample, a first 50% of the DSN address range associated with pillar 1vault 1 is mapped to storage server 1 of container 1, a first 50% of theDSN address range associated with pillar 2 vault 1 is mapped to storageserver 2 of container 1, through a first 50% of the DSN address rangeassociated with pillar 8 vault 1 is mapped to storage server 8 ofcontainer 1 and a second 50% of the DSN address range associated withpillar 1 vault 1 is mapped to storage server 1 of container 2, a second50% of the DSN address range associated with pillar 2 vault 1 is mappedto storage server 2 of container 2, through a second 50% of the DSNaddress range associated with pillar 8 vault 1 is mapped to storageserver 8 of container 2.

The container controller modifies storage of encoded data slices in thestorage servers by transferring some of the encoded data slices fromcontainer 1 to container 2. For example, slices associated with 25% ofthe DSN address range of pillar 1 of vault 1 are transferred fromstorage server 1 of container 1 to storage server 1 of container 2 andall the slices of pillar 1 of vault 1 (e.g. representing 25% of theaddress range of pillar 1 of vault 1) stored in storage server 5 ofcontainer 1 are transferred to storage server 1 of container 2. Thecontainer controller may further remap the third mapping to produce afourth mapping in a similar fashion as to the remapping discussedpreviously moving from the mapping of FIG. 9D to the mapping of FIG. 9Eas storage server utilization information indicates an unfavorablyhigher utilization level of the storage servers.

FIG. 9I is a schematic block diagram of another embodiment of acomputing system that includes a dispersed storage (DS) processing 34, aset of servers A1-A4, and two or more maintenance free storagecontainers 1-2 190. Each maintenance free storage container 190 includesa plurality of storage servers 1-U, a container controller 196, and alocal area network (LAN) 199. The servers A1-A4 include one or more of asite controller, a container controller 196, a DS processing unit 16, auser device, a server module, and a computing server.

The container controller 196 includes plurality of virtual storageservers. The container controller 196 is operable to assign a dispersedstorage network (DSN) address range to each virtual storage server andfor each virtual storage server, map the DSN address range to at leastsome of the plurality of storage serves in accordance with a mapping.For example, the container controller 196 of maintenance free storagecontainer 1 190 modifies a second mapping of virtual storage servers ofmaintenance free storage container 1 190 to produce a third mapping thatincludes mapping of the virtual storage servers of maintenance freestorage container 1 190 to storage servers 1-8 of maintenance freestorage container 1 190 and includes mapping of the virtual storageservers of maintenance free storage container 2 190 to storage servers1-8 of maintenance free storage container 2 190 when maintenance freestorage container 2 190 is added to the computing system.

The container controller 196 of maintenance free storage container 1 190may produce the third mapping in accordance with data storage adjustmentcriteria indicating how to reassign the DSN address ranges associatedwith each pillar when an additional maintenance free storage container 2190 is added to the computing system. The container controller 196determines the third mapping such that one or the other maintenance freestorage container includes virtual storage servers that each areassigned 100% of the DSN address range of a given pillar. The pillarassignments are split between the two storage controllers. For example,maintenance free storage container 1 190 includes a first virtualstorage server assigned to 100% of slice name ranges associated withvault 1 pillar 1, a second virtual storage server assigned to 100% ofslice name ranges associated with vault 1 pillar 2, a third virtualstorage server assigned to 100% of slice name ranges associated withvault 1 pillar 3, and a fourth virtual storage server assigned to 100%of slice name ranges associated with vault 1 pillar 4 and maintenancefree storage container 2 190 includes a first virtual storage serverassigned to 100% of slice name ranges associated with vault 1 pillar 5,a second virtual storage server assigned to 100% of slice name rangesassociated with vault 1 pillar 6, a third virtual storage serverassigned to 100% of slice name ranges associated with vault 1 pillar 7,and a fourth virtual storage server assigned to 100% of slice nameranges associated with vault 1 pillar 8.

Each virtual storage server may map to one or more associated storageservers. For example, the first virtual storage server of maintenancefree storage container 1 190 maps to storage servers 1 and 2 ofmaintenance free storage container 1 190, the second virtual storageserver of maintenance free storage container 1 190 maps to storageservers 3 and 4 of maintenance free storage container 1 190, the thirdvirtual storage server of maintenance free storage container 1 190 mapsto storage servers 5 and 6 of maintenance free storage container 1 190,the fourth virtual storage server of maintenance free storage container1 190 maps to storage servers 7 and 8 of maintenance free storagecontainer 1 190, and the first virtual storage server of maintenancefree storage container 2 190 maps to storage servers 1 and 2 ofmaintenance free storage container 2 190, the second virtual storageserver of maintenance free storage container 2 190 maps to storageservers 3 and 4 of maintenance free storage container 2 190, the thirdvirtual storage server of maintenance free storage container 2 190 mapsto storage servers 5 and 6 of maintenance free storage container 2 190,and the fourth virtual storage server of maintenance free storagecontainer 2 190 maps to storage servers 7 and 8 of maintenance freestorage container 2 190.

FIG. 10 is a flowchart illustrating an example of retrieving a datasegment. The method begins with step 300 where a processing module(e.g., of a dispersed storage (DS) processing unit) receives a requestto retrieve a data segment. The request may include one or more of anobject number, a file identifier (ID), a second number, and a requestingentity ID. The method continues at step 302 where the processing moduleobtains storage information. The storage information includes one ormore of a DS unit ID, a DS unit internet protocol (IP) address, a vaultID, a segmentation method, a decode threshold number, a pillar widthnumber, a maintenance free storage container topology, and an assignmentof a pillar to a container and a DS unit and/or virtual storage serverwithin the container. The obtaining may be based on one or more ofreceiving the storage information with the request, accessing aregistry, a lookup, and a predetermination.

The method continues at step 304 where the processing module sendsencoded data slice retrieval requests for a decode threshold number ofencoded data slice pillars to two or more containers. The sendingincludes generating the requests based on the storage information andthe data segment request. The sending further includes outputting theencoded data slice retrieval requests to DS units based on the storageinformation. For example, the processing module sends encoded data sliceretrieval requests for half of the decode threshold number of encodeddata slice pillars to a first container controller and sends encodeddata slice retrieval requests for a remaining half of the decodethreshold number of encoded data slice pillars to a second containercontroller to provide distributed access loading and improved retrievallatency performance.

The method continues at step 306 where the processing module receivesencoded data slices. A container controller may prioritize returningencoded data slices corresponding to primary pillars (e.g., slicesgenerated from a unity matrix within a generator matrix utilized in adispersed storage error coding function) over non-primary pillars (e.g.error coded slices generated from a portion of the generator matrix notassociated with the unity matrix). For example, a container controller 1sends encoded data slices corresponding to pillars 1 and 3 when DS units1 and 3 are available and pillars 1 and 3 are primary pillars. Asanother example, container controller 1 sends encoded data slicescorresponding to pillars 5 and 7 (e.g., non-primary pillars) when DSunits 1 and 3 are not available.

The method continues at step 308 where the processing module determineswhether a decode threshold number of encoded data slices have beenreceived by comparing a number of received encoded data slices to thedecode threshold number. The method branches to step 312 when theprocessing module determines that the decode threshold number of encodeddata slices have not been received. The method continues to step 300 andwhen the processing module determines that the decode threshold numberof encoded data slices have been received. The method continues at step310 where the processing module dispersed storage error decodes theencoded data slices to produce the data segment. The method continues atstep 312 where the processing module sends at least one encoded dataslice retrieval request for additional pillars to at least one containerwhen the processing module determines that the decode threshold numberof encoded data slices have not been received. For example, theprocessing module sends the at least one encoded data slice retrievalrequest to an additional container. As another example, the processingmodule sends the at least one encoded data slice retrieval request, foran encoded data slice corresponding to an additional pillar, to a firstcontainer controller (e.g., of a previous retrieval request). The methodbranches back to step 306 to receive another slice.

A container controller of a maintenance free storage container isoperable to facilitate access to a maintenance free storage container byreceiving a request for two or more slices from a requesting entity,wherein the slices are associated with at least two pillars, identifyingat least one priority slice of the two or more slices (e.g., identifybased on: encoding parameters, a flag, a slice name, forinstance—priority slice produced from unity matrix to enable fastsegment decode by the requesting entity), and determining anavailability level for each priority slice of the at least one priorityslice (e.g., available, not available). The container controller isfurther operable to, for each priority slice of the at least onepriority slice that is available, outputting the priority slice to therequesting entity. The container controller is further operable to, foreach priority slice of the at least one priority slice that isunavailable, facilitate rebuilding the priority slice utilizingassociated slices stored within the maintenance free storage containerto produce a rebuilt priority slice and output the rebuilt priorityslice to the requesting entity.

FIG. 11 is a flowchart illustrating an example of rebuilding an encodedslice. The method begins at step 314 where a processing module (e.g., ofa container controller of a maintenance free storage container)determines an encoded data slice to be rebuilt. The determination may bebased on one or more of a query, a lookup, an error message, detecting amissing slice, and detecting a slice with unfavorable integrityinformation. The method continues at step 316 where the processingmodule sends encoded data slice retrieval requests to each dispersedstorage (DS) unit and/or virtual storage server of a home containercorresponding to the encoded data slice to be rebuilt. The retrievalfrom the DS units of the container corresponding to the encoded dataslice to rebuild may provide a system enhancement by minimizingretrieval access latency. The method continues at step 318 where theprocessing module sends an encoded data slice retrieval request toanother container when at least a decode threshold number of encodeddata slice retrieval requests have not been sent (e.g., within the homecontainer).

The method continues at step 320 where the processing module receives adecode threshold number of encoded data slices (e.g., primarily from theDS units of the home container and at least one encoded data slice fromanother container). The method continues at step 322 where theprocessing module dispersed storage error decodes the decode thresholdnumber of encoded data slices to produce a data segment. The methodcontinues at step 324 where the processing module dispersed storageerror encodes the data segment to produce a set of encoded data slicesthat includes the encoded data slice to be rebuilt. The method continuesat step 326 where the processing module sends the rebuilt encoded dataslice to a corresponding DS unit and/or virtual storage server forstorage therein. For example, the processing module sends a writerequest message that includes the rebuilt encoded data slice to a DSunit of the home container, when the encoded data slice is missing fromthe DS unit. As another example, the processing module sends a writerequest message that includes the rebuilt encoded data slice to a fosterDS unit (e.g., a temporary storage location) associated with the homecontainer.

FIG. 12A is a schematic block diagram of another embodiment of acomputing system. The system includes a site, wherein the site includestwo maintenance free storage containers 1-2 190. The first containerincludes a container controller 1 196, a plurality of storage servers 1,3, 5, 7, and 9 (e.g., associated with odd numbered pillars), and acommon local area network (LAN) 199. The second container includes acontainer controller 2 196, a plurality of storage servers 2, 4, 6, 8,and 10 (e.g., associated with even numbered pillars), and a LAN 199. Thesystem may be associated with a pillar width to decode thresholdrelationship of >2:1, wherein the pillar width is greater than twice thedecode threshold. In such an arrangement, it is possible to retrieve adecode threshold number of encoded slices at least two ways from a set(e.g., a pillar width number of a common data segment) of encodedslices. For example, and encoded data slice of pillar 1 is stored instorage server 1, an encoded data slice of pillar 2 is stored in storageserver 2, etc. through an encoded data slice of pillar 10 is stored atstorage server 10, when a pillar width is 10 and a decode threshold is4.

A corresponding data segment may be reproduced by retrieving any 4encoded data slices of the set of 10 encoded data slices. For example,the data segment may be reproduced by retrieving encoded data slicesfrom storage servers 3, 5, 7, and 9 by facilitating access via the LAN199 associated with container 1. As another example, the data segmentmay be reproduced by retrieving encoded slices from storage servers 2,4, 6, and 8 by facilitating access via the LAN 199 associated withcontainer 2. As yet another example, the data segment may be reproducedby retrieving encoded data slices from storage servers 1-4 byfacilitating access via LAN 199 associated with container 1 and 2. Asstill another example, the data segment may be reproduced by retrievingencoded data slices from storage servers 7-10 by facilitating access viaLAN 199 associated with container 1 and 2.

In such a system, any single encoded data slice to be rebuilt andassociated with a storage server may be reproduced based on retrievingencoded data slices from other storage servers associated with a commoncontainer when all the other storage servers are available. For example,container controller 1 determines to reproduce a rebuilt encoded dataslice of DS unit 5. The container controller 1 196 retrieves a decodethreshold number of encoded data slices from storage servers 1, 3, 7,and 9 and dispersed storage error decodes the decode threshold number ofencoded data slices to reproduce a data segment. The containercontroller 1 196 dispersed storage error encodes the data segment toreproduce the rebuilt encoded data slice. The container controller 1 196sends the rebuilt encoded data slice to storage server 5 for storagetherein. The method of operation of such a rebuilding process isdescribed in greater detail with reference to FIG. 12B.

FIG. 12B is a flowchart illustrating another example of rebuilding anencoded slice, which includes similar steps to FIGS. 10 and 11. Themethod begins with steps 314 and 316 of FIG. 11 where a processingmodule (e.g. of a container controller) determines a slice to be rebuiltand sends slice retrieval requests to each DS unit (e.g., virtualstorage server) of a home container corresponding to the slice to berebuilt. The method continues with steps 306 and 308 of FIG. 10 wherethe processing module receives encoded data slices and determineswhether a decode threshold number of encoded data slices have beenreceived. The method branches to step 322 of FIG. 11 when the processingmodule determines that the decode threshold number of encoded dataslices have been received. The method continues to step 318 of FIG. 11when the processing module determines that the decode threshold numberof encoded data slices have not been received. The method continues withstep 318 of FIG. 11 where the processing module sends an encoded dataslice retrieval request to another container. The method loops back tostep 306 of FIG. 10 to receive another slice.

The method continues with steps 322-316 of FIG. 11 where the processingmodule dispersed storage error decodes the decode threshold number ofencoded data slices to produce a data segment, dispersed storage errorencodes the data segment to produce the encoded data slice to berebuilt, and sends the rebuilt encoded data slice to a corresponding DSunit for storage therein when the processing module determines that thedecode threshold number of encoded data slices have been received.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “operably coupled to”, “coupled to”, and/or “coupling” includesdirect coupling between items and/or indirect coupling between items viaan intervening item (e.g., an item includes, but is not limited to, acomponent, an element, a circuit, and/or a module) where, for indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.As may even further be used herein, the term “operable to” or “operablycoupled to” indicates that an item includes one or more of powerconnections, input(s), output(s), etc., to perform, when activated, oneor more its corresponding functions and may further include inferredcoupling to one or more other items. As may still further be usedherein, the term “associated with”, includes direct and/or indirectcoupling of separate items and/or one item being embedded within anotheritem. As may be used herein, the term “compares favorably”, indicatesthat a comparison between two or more items, signals, etc., provides adesired relationship. For example, when the desired relationship is thatsignal 1 has a greater magnitude than signal 2, a favorable comparisonmay be achieved when the magnitude of signal 1 is greater than that ofsignal 2 or when the magnitude of signal 2 is less than that of signal1.

As may also be used herein, the terms “processing module”, “processingcircuit”, and/or “processing unit” may be a single processing device ora plurality of processing devices. Such a processing device may be amicroprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on hard coding of the circuitry and/oroperational instructions. The processing module, module, processingcircuit, and/or processing unit may be, or further include, memoryand/or an integrated memory element, which may be a single memorydevice, a plurality of memory devices, and/or embedded circuitry ofanother processing module, module, processing circuit, and/or processingunit. Such a memory device may be a read-only memory, random accessmemory, volatile memory, non-volatile memory, static memory, dynamicmemory, flash memory, cache memory, and/or any device that storesdigital information. Note that if the processing module, module,processing circuit, and/or processing unit includes more than oneprocessing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

The present invention has been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention. Further, theboundaries of these functional building blocks have been arbitrarilydefined for convenience of description. Alternate boundaries could bedefined as long as the certain significant functions are appropriatelyperformed. Similarly, flow diagram blocks may also have been arbitrarilydefined herein to illustrate certain significant functionality. To theextent used, the flow diagram block boundaries and sequence could havebeen defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claimed invention. One of average skill in the artwill also recognize that the functional building blocks, and otherillustrative blocks, modules and components herein, can be implementedas illustrated or by discrete components, application specificintegrated circuits, processors executing appropriate software and thelike or any combination thereof.

The present invention may have also been described, at least in part, interms of one or more embodiments. An embodiment of the present inventionis used herein to illustrate the present invention, an aspect thereof, afeature thereof, a concept thereof, and/or an example thereof. Aphysical embodiment of an apparatus, an article of manufacture, amachine, and/or of a process that embodies the present invention mayinclude one or more of the aspects, features, concepts, examples, etc.described with reference to one or more of the embodiments discussedherein. Further, from figure to figure, the embodiments may incorporatethe same or similarly named functions, steps, modules, etc. that may usethe same or different reference numbers and, as such, the functions,steps, modules, etc. may be the same or similar functions, steps,modules, etc. or different ones.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of the various embodimentsof the present invention. A module includes a processing module, afunctional block, hardware, and/or software stored on memory forperforming one or more functions as may be described herein. Note that,if the module is implemented via hardware, the hardware may operateindependently and/or in conjunction software and/or firmware. As usedherein, a module may contain one or more sub-modules, each of which maybe one or more modules.

While particular combinations of various functions and features of thepresent invention have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent invention is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

What is claimed is:
 1. A method comprises: sending, by a computingdevice, an access request to one or more site controllers, wherein theaccess request is regarding one or more sets of encoded data sliceshaving one or more sets of dispersed storage network (DSN) addresses;identifying, by the one or more site controllers, one or more storagecontainers based on the one or more sets of DSN addresses, wherein astorage container of the one or more storage containers includes acontainer controller and a plurality of storage units, wherein a storageunit of the plurality of storage units includes a plurality of storagedevices; sending, by the one or more site controllers, the accessrequest to the one or more identified storage containers; interpreting,by a container controller of one of the one or more identified storagecontainers, the access request to identify one or more storage units ofthe plurality of storage units affiliated with one or more DSN addressesof the one or more sets of DSN addresses; determining, by the containercontroller, whether the one or more storage units is in a storagefailure mode with regard to the one or more DSN addresses; when the oneor more storage units is in the storage failure mode, determining, bythe container controller, whether to rebuild, to change virtual tophysical address mapping, or to migrate one or more encoded data slicesof the one or more sets of encoded data slices associated with the oneor more DSN addresses concerning the failure mode; and when the one ormore encoded data slices is to be rebuilt, facilitating, by thecontainer controller, rebuilding of the one or more encoded data slices.2. The method of claim 1, wherein the storage failure mode comprises oneof: a storage location failure within a storage device of the pluralityof storage devices of the storage unit; a storage device failure withinthe storage unit; a storage unit failure; a missing encoded data slice;and a corrupted encoded data slice.
 3. The method of claim 1, whereinthe access request comprises one of: a read request; a write request;and a data storage integrity verification.
 4. The method of claim 1further comprises: when the one or more storage units is in the storagefailure mode and the container controller determines to rebuild anencoded data slice of the one or more encoded data slices: determining,by the container controller, whether a decode threshold number ofencoded data slices of a set of encoded data slices of the one or moresets of encoded data slices is stored in the plurality of storage unitswithin the storage container that includes the container controller,wherein the set of encoded data slices includes the encoded data slice;and when the decode threshold number of encoded data slices is stored inthe plurality of storage units, rebuilding, by the container controller,the encoded data slice based on the decode threshold number of encodeddata slices.
 5. The method of claim 4 further comprises: when the decodethreshold number of encoded data slices is not stored in the pluralityof storage units, forwarding, by the container controller, a rebuildrequest for the encoded data slices to a site controller of the one ormore site controllers; retrieving, by the site controller, the decodethreshold number of encoded data slices from a plurality of storagecontainers of the one or more storage containers; and rebuilding, by thesite controller, the encoded data slice based on the decode thresholdnumber of encoded data slices.
 6. The method of claim 1 furthercomprises: when the one or more storage units is in the storage failuremode and the container controller determines to migrate the one or moreencoded data slices: determining, by the container controller, whetherthe one or more sets of encoded data slices are stored in the pluralityof storage units within the storage container that includes thecontainer controller, wherein the set of encoded data slices includesthe one or more encoded data slices; and when the one or more encodeddata slices are stored in the plurality of storage units, migrating, bythe container controller, the one or more encoded data slices todifferent storage locations within the plurality of storage units. 7.The method of claim 6 further comprises: when the one or more encodeddata slices are not stored in the plurality of storage units,forwarding, by the container controller, a migrate request a sitecontroller of the one or more site controllers; and migrating, by thesite controller, the one or more encoded data slices to differentstorage containers of the plurality of storage containers.
 8. The methodof claim 1 further comprises: when the one or more storage units is inthe storage failure mode and the container controller determines tochange virtual to physical address mapping for the one or more encodeddata slices: detecting, by the container controller, a failure of aphysical storage location within the plurality of storage units of thestorage container, wherein the storage location is mapped to a DSNaddress of the one or more DSN addresses; identifying, by the containercontroller, a different physical address location within the pluralityof storage units that has not failed; and mapping the DSN address to thedifferent physical address location.
 9. A non-transitory computerreadable storage device comprises: a first storage section that storesoperational instructions that, when executed by a computing device,causes the computing device to: send an access request to one or moresite controllers, wherein the access request is regarding one or moresets of encoded data slices having one or more sets of dispersed storagenetwork (DSN) addresses; a second storage section that storesoperational instructions that, when executed by a site controller of theone or more site controllers, causes the site controller to: identifyone or more storage containers based on the one or more sets of DSNaddresses, wherein a storage container of the one or more storagecontainers includes a container controller and a plurality of storageunits, wherein a storage unit of the plurality of storage units includesa plurality of storage devices; and send the access request to the oneor more identified storage containers; a third storage section thatstores operational instructions that, when executed by a containercontroller of the one or more container controllers, causes thecontainer controller to: interpret the access request to identify one ormore storage units of the plurality of storage units affiliated with oneor more DSN addresses of the one or more sets of DSN addresses;determine whether the one or more storage units is in a storage failuremode with regard to the one or more DSN addresses; when the one or morestorage units is in the storage failure mode, determine whether torebuild, to change virtual to physical address mapping, or to migrateone or more encoded data slices of the one or more sets of encoded dataslices associated with the one or more DSN addresses concerning thefailure mode; and when the one or more encoded data slices is to berebuilt, facilitate rebuilding of the one or more encoded data slices.10. The non-transitory computer readable storage device of claim 9,wherein the storage failure mode comprises one of: a storage locationfailure within a storage device of the plurality of storage devices ofthe storage unit; a storage device failure within the storage unit; astorage unit failure; a missing encoded data slice; and a corruptedencoded data slice.
 11. The non-transitory computer readable storagedevice of claim 9, wherein the access request comprises one of: a readrequest; a write request; and a data storage integrity verification. 12.The non-transitory computer readable storage device of claim 9 furthercomprises: a fourth storage section that stores operational instructionsthat, when executed by the container controller, causes the containercontroller to: when the one or more storage units is in the storagefailure mode and the container controller determines to rebuild anencoded data slice of the one or more encoded data slices: determinewhether a decode threshold number of encoded data slices of a set ofencoded data slices of the one or more sets of encoded data slices isstored in the plurality of storage units within the storage containerthat includes the container controller, wherein the set of encoded dataslices includes the encoded data slice; and when the decode thresholdnumber of encoded data slices is stored in the plurality of storageunits, rebuild the encoded data slice based on the decode thresholdnumber of encoded data slices.
 13. The non-transitory computer readablestorage device of claim 12 further comprises: the fourth storage sectionfurther stores operational instructions that, when executed by thecontainer controller, causes the container controller to: when thedecode threshold number of encoded data slices is not stored in theplurality of storage units, forward a rebuild request for the encodeddata slices to a site controller of the one or more site controllers; afifth storage section that stores operational instructions that, whenexecuted by the site controller, causes the site controller to: retrievethe decode threshold number of encoded data slices from a plurality ofstorage containers of the one or more storage containers; and rebuildthe encoded data slice based on the decode threshold number of encodeddata slices.
 14. The non-transitory computer readable storage device ofclaim 9 further comprises: a fourth storage section that storesoperational instructions that, when executed by the containercontroller, causes the container controller to: when the one or morestorage units is in the storage failure mode and the containercontroller determines to migrate the one or more encoded data slices:determine whether the one or more sets of encoded data slices are storedin the plurality of storage units within the storage container thatincludes the container controller, wherein the set of encoded dataslices includes the one or more encoded data slices; and when the one ormore encoded data slices are stored in the plurality of storage units,migrate the one or more encoded data slices to different storagelocations within the plurality of storage units.
 15. The non-transitorycomputer readable storage device of claim 14 further comprises: thefourth storage section further stores operational instructions that,when executed by the container controller, causes the containercontroller to: when the one or more encoded data slices are not storedin the plurality of storage units, forward a migrate request a sitecontroller of the one or more site controllers; and a fifth storagesection that stores operational instructions that, when executed by thesite controller, causes the site controller to: migrate the one or moreencoded data slices to different storage containers of the plurality ofstorage containers.
 16. The non-transitory computer readable storagedevice of claim 9 further comprises: a fourth storage section thatstores operational instructions that, when executed by the containercontroller, causes the container controller to: when the one or morestorage units is in the storage failure mode and the containercontroller determines to change virtual to physical address mapping forthe one or more encoded data slices: detect a failure of a physicalstorage location within the plurality of storage units of the storagecontainer, wherein the storage location is mapped to a DSN address ofthe one or more DSN addresses; identify a different physical addresslocation within the plurality of storage units that has not failed; andmap the DSN address to the different physical address location.